diff --git a/compose.yml b/compose.yml
index 6ae60976..fe967be2 100644
--- a/compose.yml
+++ b/compose.yml
@@ -23,6 +23,7 @@ services:
     volumes:
       - ./local-instances/${INSTANCE:-0}/www:/var/www
       - ./docker/php/www.conf:/usr/local/etc/php-fpm.d/www.conf
+      - redis-sock:/var/run/redis
 
   #MySQL Service
   db:
@@ -36,3 +37,13 @@ services:
       MYSQL_ROOT_PASSWORD: password
     volumes:
       - ./local-instances/${INSTANCE:-0}/mysql:/var/lib/mysql
+
+  redis:
+    build:
+      context: ./
+      dockerfile: ./docker/redis/Dockerfile
+    volumes:
+      - redis-sock:/var/run/redis
+
+volumes:
+  redis-sock:
diff --git a/composer.json b/composer.json
index 86692db4..d0345e3b 100644
--- a/composer.json
+++ b/composer.json
@@ -13,6 +13,7 @@
         "files": [
             "inc/anti-bot.php",
             "inc/bootstrap.php",
+            "inc/context.php",
             "inc/display.php",
             "inc/template.php",
             "inc/database.php",
diff --git a/docker/redis/Dockerfile b/docker/redis/Dockerfile
new file mode 100644
index 00000000..9ab7f7fc
--- /dev/null
+++ b/docker/redis/Dockerfile
@@ -0,0 +1,6 @@
+FROM redis:7.4-alpine
+
+RUN mkdir -p /var/run/redis && chmod 777 /var/run/redis
+COPY ./docker/redis/redis.conf /etc/redis.conf
+
+ENTRYPOINT [ "docker-entrypoint.sh", "/etc/redis.conf" ]
diff --git a/docker/redis/redis.conf b/docker/redis/redis.conf
new file mode 100644
index 00000000..609d57ff
--- /dev/null
+++ b/docker/redis/redis.conf
@@ -0,0 +1,16 @@
+# Accept connections on the specified port, default is 6379 (IANA #815344).
+# If port 0 is specified Redis will not listen on a TCP socket.
+#port 6379
+port 0
+
+# Unix socket.
+#
+# Specify the path for the Unix socket that will be used to listen for
+# incoming connections. There is no default, so Redis will not listen
+# on a unix socket when not specified.
+#
+unixsocket /var/run/redis/redis-server.sock
+# Executig a socket is a no-op, and we need to share acces to other programs.
+# Shared the connection only with programs in the redis group for security.
+#unixsocketperm 700
+unixsocketperm 666
diff --git a/inc/Data/Driver/ApcuCacheDriver.php b/inc/Data/Driver/ApcuCacheDriver.php
new file mode 100644
index 00000000..a39bb656
--- /dev/null
+++ b/inc/Data/Driver/ApcuCacheDriver.php
@@ -0,0 +1,28 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+class ApcuCacheDriver implements CacheDriver {
+	public function get(string $key): mixed {
+		$success = false;
+		$ret = \apcu_fetch($key, $success);
+		if ($success === false) {
+			return null;
+		}
+		return $ret;
+	}
+
+	public function set(string $key, mixed $value, mixed $expires = false): void {
+		\apcu_store($key, $value, (int)$expires);
+	}
+
+	public function delete(string $key): void {
+		\apcu_delete($key);
+	}
+
+	public function flush(): void {
+		\apcu_clear_cache();
+	}
+}
diff --git a/inc/Data/Driver/ArrayCacheDriver.php b/inc/Data/Driver/ArrayCacheDriver.php
new file mode 100644
index 00000000..bb0cd310
--- /dev/null
+++ b/inc/Data/Driver/ArrayCacheDriver.php
@@ -0,0 +1,28 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+/**
+ * A simple process-wide PHP array.
+ */
+class ArrayCacheDriver implements CacheDriver {
+	private static array $inner = [];
+
+	public function get(string $key): mixed {
+		return isset(self::$inner[$key]) ? self::$inner[$key] : null;
+	}
+
+	public function set(string $key, mixed $value, mixed $expires = false): void {
+		self::$inner[$key] = $value;
+	}
+
+	public function delete(string $key): void {
+		unset(self::$inner[$key]);
+	}
+
+	public function flush(): void {
+		self::$inner = [];
+	}
+}
diff --git a/inc/Data/Driver/CacheDriver.php b/inc/Data/Driver/CacheDriver.php
new file mode 100644
index 00000000..083ed652
--- /dev/null
+++ b/inc/Data/Driver/CacheDriver.php
@@ -0,0 +1,38 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+interface CacheDriver {
+	/**
+	 * Get the value of associated with the key.
+	 *
+	 * @param string $key The key of the value.
+	 * @return mixed|null The value associated with the key, or null if there is none.
+	 */
+	public function get(string $key): mixed;
+
+	/**
+	 * Set a key-value pair.
+	 *
+	 * @param string $key The key.
+	 * @param mixed $value The value.
+	 * @param int|false $expires After how many seconds the pair will expire. Use false or ignore this parameter to keep
+	 *                           the value until it gets evicted to make space for more items. Some drivers will always
+	 *                           ignore this parameter and store the pair until it's removed.
+	 */
+	public function set(string $key, mixed $value, mixed $expires = false): void;
+
+	/**
+	 * Delete a key-value pair.
+	 *
+	 * @param string $key The key.
+	 */
+	public function delete(string $key): void;
+
+	/**
+	 * Delete all the key-value pairs.
+	 */
+	public function flush(): void;
+}
diff --git a/inc/Data/Driver/FsCachedriver.php b/inc/Data/Driver/FsCachedriver.php
new file mode 100644
index 00000000..b543cfa6
--- /dev/null
+++ b/inc/Data/Driver/FsCachedriver.php
@@ -0,0 +1,155 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+class FsCacheDriver implements CacheDriver {
+	private string $prefix;
+	private string $base_path;
+	private mixed $lock_fd;
+	private int|false $collect_chance_den;
+
+
+	private function prepareKey(string $key): string {
+		$key = \str_replace('/', '::', $key);
+		$key = \str_replace("\0", '', $key);
+		return $this->prefix . $key;
+	}
+
+	private function sharedLockCache(): void {
+		\flock($this->lock_fd, LOCK_SH);
+	}
+
+	private function exclusiveLockCache(): void {
+		\flock($this->lock_fd, LOCK_EX);
+	}
+
+	private function unlockCache(): void {
+		\flock($this->lock_fd, LOCK_UN);
+	}
+
+	private function collectImpl(): int {
+		/*
+		 * A read lock is ok, since it's alright if we delete expired items from under the feet of other processes, and
+		 * no other process add new cache items or refresh existing ones.
+		 */
+		$files = \glob($this->base_path . $this->prefix . '*', \GLOB_NOSORT);
+		$count = 0;
+		foreach ($files as $file) {
+			$data = \file_get_contents($file);
+			$wrapped = \json_decode($data, true, 512, \JSON_THROW_ON_ERROR);
+			if ($wrapped['expires'] !== false && $wrapped['expires'] <= \time()) {
+				if (@\unlink($file)) {
+					$count++;
+				}
+			}
+		}
+		return $count;
+	}
+
+	private function maybeCollect(): void {
+		if ($this->collect_chance_den !== false && \mt_rand(0, $this->collect_chance_den - 1) === 0) {
+			$this->collect_chance_den = false; // Collect only once per instance (aka process).
+			$this->collectImpl();
+		}
+	}
+
+	public function __construct(string $prefix, string $base_path, string $lock_file, int|false $collect_chance_den) {
+		if ($base_path[\strlen($base_path) - 1] !== '/') {
+			$base_path = "$base_path/";
+		}
+
+		if (!\is_dir($base_path)) {
+			throw new \RuntimeException("$base_path is not a directory!");
+		}
+
+		if (!\is_writable($base_path)) {
+			throw new \RuntimeException("$base_path is not writable!");
+		}
+
+		$this->lock_fd = \fopen($base_path . $lock_file, 'w');
+		if ($this->lock_fd === false) {
+			throw new \RuntimeException('Unable to open the lock file!');
+		}
+
+		$this->prefix = $prefix;
+		$this->base_path = $base_path;
+		$this->collect_chance_den = $collect_chance_den;
+	}
+
+	public function __destruct() {
+		$this->close();
+	}
+
+	public function get(string $key): mixed {
+		$key = $this->prepareKey($key);
+
+		$this->sharedLockCache();
+
+		// Collect expired items first so if the target key is expired we shortcut to failure in the next lines.
+		$this->maybeCollect();
+
+		$fd = \fopen($this->base_path . $key, 'r');
+		if ($fd === false) {
+			$this->unlockCache();
+			return null;
+		}
+
+		$data = \stream_get_contents($fd);
+		\fclose($fd);
+		$this->unlockCache();
+		$wrapped = \json_decode($data, true, 512, \JSON_THROW_ON_ERROR);
+
+		if ($wrapped['expires'] !== false && $wrapped['expires'] <= \time()) {
+			// Already expired, leave it there since we already released the lock and pretend it doesn't exist.
+			return null;
+		} else {
+			return $wrapped['inner'];
+		}
+	}
+
+	public function set(string $key, mixed $value, mixed $expires = false): void {
+		$key = $this->prepareKey($key);
+
+		$wrapped = [
+			'expires' => $expires ? \time() + $expires : false,
+			'inner' => $value
+		];
+
+		$data = \json_encode($wrapped);
+		$this->exclusiveLockCache();
+		$this->maybeCollect();
+		\file_put_contents($this->base_path . $key, $data);
+		$this->unlockCache();
+	}
+
+	public function delete(string $key): void {
+		$key = $this->prepareKey($key);
+
+		$this->exclusiveLockCache();
+		@\unlink($this->base_path . $key);
+		$this->maybeCollect();
+		$this->unlockCache();
+	}
+
+	public function collect(): int {
+		$this->sharedLockCache();
+		$count = $this->collectImpl();
+		$this->unlockCache();
+		return $count;
+	}
+
+	public function flush(): void {
+		$this->exclusiveLockCache();
+		$files = \glob($this->base_path . $this->prefix . '*', \GLOB_NOSORT);
+		foreach ($files as $file) {
+			@\unlink($file);
+		}
+		$this->unlockCache();
+	}
+
+	public function close(): void {
+		\fclose($this->lock_fd);
+	}
+}
diff --git a/inc/Data/Driver/MemcacheCacheDriver.php b/inc/Data/Driver/MemcacheCacheDriver.php
new file mode 100644
index 00000000..04f62895
--- /dev/null
+++ b/inc/Data/Driver/MemcacheCacheDriver.php
@@ -0,0 +1,43 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+class MemcachedCacheDriver implements CacheDriver {
+	private \Memcached $inner;
+
+	public function __construct(string $prefix, string $memcached_server) {
+		$this->inner = new \Memcached();
+		if (!$this->inner->setOption(\Memcached::OPT_BINARY_PROTOCOL, true)) {
+			throw new \RuntimeException('Unable to set the memcached protocol!');
+		}
+		if (!$this->inner->setOption(\Memcached::OPT_PREFIX_KEY, $prefix)) {
+			throw new \RuntimeException('Unable to set the memcached prefix!');
+		}
+		if (!$this->inner->addServers($memcached_server)) {
+			throw new \RuntimeException('Unable to add the memcached server!');
+		}
+	}
+
+	public function get(string $key): mixed {
+		$ret = $this->inner->get($key);
+		// If the returned value is false but the retrival was a success, then the value stored was a boolean false.
+		if ($ret === false && $this->inner->getResultCode() !== \Memcached::RES_SUCCESS) {
+			return null;
+		}
+		return $ret;
+	}
+
+	public function set(string $key, mixed $value, mixed $expires = false): void {
+		$this->inner->set($key, $value, (int)$expires);
+	}
+
+	public function delete(string $key): void {
+		$this->inner->delete($key);
+	}
+
+	public function flush(): void {
+		$this->inner->flush();
+	}
+}
diff --git a/inc/Data/Driver/NoneCacheDriver.php b/inc/Data/Driver/NoneCacheDriver.php
new file mode 100644
index 00000000..8b260a50
--- /dev/null
+++ b/inc/Data/Driver/NoneCacheDriver.php
@@ -0,0 +1,26 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+/**
+ * No-op cache. Useful for testing.
+ */
+class NoneCacheDriver implements CacheDriver {
+	public function get(string $key): mixed {
+		return null;
+	}
+
+	public function set(string $key, mixed $value, mixed $expires = false): void {
+		// No-op.
+	}
+
+	public function delete(string $key): void {
+		// No-op.
+	}
+
+	public function flush(): void {
+		// No-op.
+	}
+}
diff --git a/inc/Data/Driver/RedisCacheDriver.php b/inc/Data/Driver/RedisCacheDriver.php
new file mode 100644
index 00000000..389fff32
--- /dev/null
+++ b/inc/Data/Driver/RedisCacheDriver.php
@@ -0,0 +1,70 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+class RedisCacheDriver implements CacheDriver {
+	private string $prefix;
+	private \Redis $inner;
+
+	public function __construct(string $prefix, string $host, ?int $port, ?string $password, int $database) {
+		$this->inner = new \Redis();
+		if (str_starts_with($host, 'unix:') || str_starts_with($host, ':')) {
+			$ret = \explode(':', $host);
+			if (count($ret) < 2) {
+				throw new \RuntimeException("Invalid unix socket path $host");
+			}
+			// Unix socket.
+			$this->inner->connect($ret[1]);
+		} elseif ($port === null) {
+			$this->inner->connect($host);
+		} else {
+			// IP + port.
+			$this->inner->connect($host, $port);
+		}
+		if ($password) {
+			$this->inner->auth($password);
+		}
+		if (!$this->inner->setOption(\Redis::OPT_SERIALIZER, \Redis::SERIALIZER_JSON)) {
+			throw new \RuntimeException('Unable to configure Redis serializer');
+		}
+		if (!$this->inner->select($database)) {
+			throw new \RuntimeException('Unable to connect to Redis database!');
+		}
+
+		$this->prefix = $prefix;
+	}
+
+	public function get(string $key): mixed {
+		$ret = $this->inner->get($this->prefix . $key);
+		if ($ret === false) {
+			return null;
+		}
+		if ($ret === null) {
+			return false;
+		}
+		return $ret;
+	}
+
+	public function set(string $key, mixed $value, mixed $expires = false): void {
+		$value = $value === false ? null : $value;
+		if ($expires === false) {
+			$this->inner->set($this->prefix . $key, $value);
+		} else {
+			$this->inner->setEx($this->prefix . $key, $expires, $value);
+		}
+	}
+
+	public function delete(string $key): void {
+		$this->inner->del($this->prefix . $key);
+	}
+
+	public function flush(): void {
+		if (empty($this->prefix)) {
+			$this->inner->flushDB();
+		} else {
+			$this->inner->unlink($this->inner->keys("{$this->prefix}*"));
+		}
+	}
+}
diff --git a/inc/cache.php b/inc/cache.php
index 3f1b8cb1..293660fd 100644
--- a/inc/cache.php
+++ b/inc/cache.php
@@ -4,183 +4,89 @@
  *  Copyright (c) 2010-2013 Tinyboard Development Group
  */
 
+use Vichan\Data\Driver\{CacheDriver, ApcuCacheDriver, ArrayCacheDriver, FsCacheDriver, MemcachedCacheDriver, NoneCacheDriver, RedisCacheDriver};
+
 defined('TINYBOARD') or exit;
 
+
 class Cache {
-	private static $cache;
-	public static function init() {
+	private static function buildCache(): CacheDriver {
 		global $config;
 
 		switch ($config['cache']['enabled']) {
 			case 'memcached':
-				self::$cache = new Memcached();
-				self::$cache->addServers($config['cache']['memcached']);
-				break;
+				return new MemcachedCacheDriver(
+					$config['cache']['prefix'],
+					$config['cache']['memcached']
+				);
 			case 'redis':
-				self::$cache = new Redis();
-
-				$ret = explode(':', $config['cache']['redis'][0]);
-				if (count($ret) > 0) {
-					// Unix socket.
-					self::$cache->connect($ret[1]);
-				} else {
-					// IP + port.
-					self::$cache->connect($ret[0], $config['cache']['redis'][1]);
-				}
-
-				if ($config['cache']['redis'][2]) {
-					self::$cache->auth($config['cache']['redis'][2]);
-				}
-				self::$cache->select($config['cache']['redis'][3]) or die('cache select failure');
-				break;
+				return new RedisCacheDriver(
+					$config['cache']['prefix'],
+					$config['cache']['redis'][0],
+					$config['cache']['redis'][1],
+					$config['cache']['redis'][2],
+					$config['cache']['redis'][3]
+				);
+			case 'apcu':
+				return new ApcuCacheDriver;
+			case 'fs':
+				return new FsCacheDriver(
+					$config['cache']['prefix'],
+					"tmp/cache/{$config['cache']['prefix']}",
+					'.lock',
+					$config['auto_maintenance'] ? 1000 : false
+				);
+			case 'none':
+				return new NoneCacheDriver();
 			case 'php':
-				self::$cache = array();
-				break;
+			default:
+				return new ArrayCacheDriver();
 		}
 	}
+
+	public static function getCache(): CacheDriver {
+		static $cache;
+		return $cache ??= self::buildCache();
+	}
+
 	public static function get($key) {
 		global $config, $debug;
 
-		$key = $config['cache']['prefix'] . $key;
-
-		$data = false;
-		switch ($config['cache']['enabled']) {
-			case 'memcached':
-				if (!self::$cache)
-					self::init();
-				$data = self::$cache->get($key);
-				break;
-			case 'apc':
-				$data = apc_fetch($key);
-				break;
-			case 'xcache':
-				$data = xcache_get($key);
-				break;
-			case 'php':
-				$data = isset(self::$cache[$key]) ? self::$cache[$key] : false;
-				break;
-			case 'fs':
-				$key = str_replace('/', '::', $key);
-				$key = str_replace("\0", '', $key);
-				if (!file_exists('tmp/cache/'.$key)) {
-					$data = false;
-				}
-				else {
-					$data = file_get_contents('tmp/cache/'.$key);
-					$data = json_decode($data, true);
-				}
-				break;
-			case 'redis':
-				if (!self::$cache)
-					self::init();
-				$ret = self::$cache->get($key);
-				$data = $ret !== false ? json_decode($ret, true) : false;
-				break;
+		$ret = self::getCache()->get($key);
+		if ($ret === null) {
+			$ret = false;
 		}
 
-		if ($config['debug'])
-			$debug['cached'][] = $key . ($data === false ? ' (miss)' : ' (hit)');
+		if ($config['debug']) {
+			$debug['cached'][] = $config['cache']['prefix'] . $key . ($ret === false ? ' (miss)' : ' (hit)');
+		}
 
-		return $data;
+		return $ret;
 	}
 	public static function set($key, $value, $expires = false) {
 		global $config, $debug;
 
-		$key = $config['cache']['prefix'] . $key;
-
-		if (!$expires)
+		if (!$expires) {
 			$expires = $config['cache']['timeout'];
-
-		switch ($config['cache']['enabled']) {
-			case 'memcached':
-				if (!self::$cache)
-					self::init();
-				self::$cache->set($key, $value, $expires);
-				break;
-			case 'redis':
-				if (!self::$cache)
-					self::init();
-				self::$cache->setEx($key, $expires, json_encode($value));
-				break;
-			case 'apc':
-				apc_store($key, $value, $expires);
-				break;
-			case 'xcache':
-				xcache_set($key, $value, $expires);
-				break;
-			case 'fs':
-				$key = str_replace('/', '::', $key);
-				$key = str_replace("\0", '', $key);
-				file_put_contents('tmp/cache/'.$key, json_encode($value));
-				break;
-			case 'php':
-				self::$cache[$key] = $value;
-				break;
 		}
 
-		if ($config['debug'])
-			$debug['cached'][] = $key . ' (set)';
+		self::getCache()->set($key, $value, $expires);
+
+		if ($config['debug']) {
+			$debug['cached'][] = $config['cache']['prefix'] . $key . ' (set)';
+		}
 	}
 	public static function delete($key) {
 		global $config, $debug;
 
-		$key = $config['cache']['prefix'] . $key;
+		self::getCache()->delete($key);
 
-		switch ($config['cache']['enabled']) {
-			case 'memcached':
-				if (!self::$cache)
-					self::init();
-				self::$cache->delete($key);
-				break;
-			case 'redis':
-				if (!self::$cache)
-					self::init();
-				self::$cache->del($key);
-				break;
-			case 'apc':
-				apc_delete($key);
-				break;
-			case 'xcache':
-				xcache_unset($key);
-				break;
-			case 'fs':
-				$key = str_replace('/', '::', $key);
-				$key = str_replace("\0", '', $key);
-				@unlink('tmp/cache/'.$key);
-				break;
-			case 'php':
-				unset(self::$cache[$key]);
-				break;
+		if ($config['debug']) {
+			$debug['cached'][] = $config['cache']['prefix'] . $key . ' (deleted)';
 		}
-
-		if ($config['debug'])
-			$debug['cached'][] = $key . ' (deleted)';
 	}
 	public static function flush() {
-		global $config;
-
-		switch ($config['cache']['enabled']) {
-			case 'memcached':
-				if (!self::$cache)
-					self::init();
-				return self::$cache->flush();
-			case 'apc':
-				return apc_clear_cache('user');
-			case 'php':
-				self::$cache = array();
-				break;
-			case 'fs':
-				$files = glob('tmp/cache/*');
-				foreach ($files as $file) {
-					unlink($file);
-				}
-				break;
-			case 'redis':
-				if (!self::$cache)
-					self::init();
-				return self::$cache->flushDB();
-		}
-
+		self::getCache()->flush();
 		return false;
 	}
 }
diff --git a/inc/config.php b/inc/config.php
index 92184fc8..633cdd33 100644
--- a/inc/config.php
+++ b/inc/config.php
@@ -117,18 +117,26 @@
 
     /*
      * On top of the static file caching system, you can enable the additional caching system which is
-     * designed to minimize SQL queries and can significantly increase speed when posting or using the
-     * moderator interface. APC is the recommended method of caching.
+     * designed to minimize request processing can significantly increase speed when posting or using
+     * the moderator interface.
      *
-     * http://tinyboard.org/docs/index.php?p=Config/Cache
+     * https://github.com/vichan-devel/vichan/wiki/cache
      */
 
+    // Uses a PHP array. MUST NOT be used in multiprocess environments.
     $config['cache']['enabled'] = 'php';
-    // $config['cache']['enabled'] = 'xcache';
-    // $config['cache']['enabled'] = 'apc';
+    // The recommended in-memory method of caching. Requires the extension. Due to how APCu works, this should be
+    // disabled when you run tools from the cli.
+    // $config['cache']['enabled'] = 'apcu';
+    // The Memcache server. Requires the memcached extension, with a final D.
     // $config['cache']['enabled'] = 'memcached';
+    // The Redis server. Requires the extension.
     // $config['cache']['enabled'] = 'redis';
+    // Use the local cache folder. Slower than native but available out of the box and compatible with multiprocess
+    // environments. You can mount a ram-based filesystem in the cache directory to improve performance.
     // $config['cache']['enabled'] = 'fs';
+    // Technically available, offers a no-op fake cache. Don't use this outside of testing or debugging.
+    // $config['cache']['enabled'] = 'none';
 
     // Timeout for cached objects such as posts and HTML.
     $config['cache']['timeout'] = 60 * 60 * 48; // 48 hours
@@ -144,7 +152,7 @@
     // Redis server to use. Location, port, password, database id.
     // Note that Tinyboard may clear the database at times, so you may want to pick a database id just for
     // Tinyboard to use.
-    $config['cache']['redis'] = array('localhost', 6379, '', 1);
+    $config['cache']['redis'] = [ 'localhost', 6379, null, 1 ];
 
     // EXPERIMENTAL: Should we cache configs? Warning: this changes board behaviour, i'd say, a lot.
     // If you have any lambdas/includes present in your config, you should move them to instance-functions.php
@@ -722,18 +730,18 @@
     // a link to an email address or IRC chat room to appeal the ban.
     $config['ban_page_extra'] = '';
 
-	// Pre-configured ban reasons that pre-fill the ban form when clicked.
-	// To disable, set $config['ban_reasons'] = false;
-	$config['ban_reasons'] = array(
-		array(  'reason' =>  'Low-quality posting',
-				'length' =>  '1d'),
-		array(  'reason' =>  'Off-topic',
-				'length' =>  '1d'),
-		array(  'reason' =>  'Ban evasion',
-				'length' =>  '30d'),
-		array(  'reason' =>  'Illegal content',
-				'length' =>  ''),
-	);
+    // Pre-configured ban reasons that pre-fill the ban form when clicked.
+    // To disable, set $config['ban_reasons'] = false;
+    $config['ban_reasons'] = array(
+        array(  'reason' =>  'Low-quality posting',
+                'length' =>  '1d'),
+        array(  'reason' =>  'Off-topic',
+                'length' =>  '1d'),
+        array(  'reason' =>  'Ban evasion',
+                'length' =>  '30d'),
+        array(  'reason' =>  'Illegal content',
+                'length' =>  ''),
+    );
 
     // How often (minimum) to purge the ban list of expired bans (which have been seen).
     $config['purge_bans'] = 60 * 60 * 12; // 12 hours
@@ -1912,15 +1920,15 @@
         'max_message_length' => 240
     ];
 
-	//Securimage captcha
-	//Note from lainchan PR: "TODO move a bunch of things here"
+    //Securimage captcha
+    //Note from lainchan PR: "TODO move a bunch of things here"
 
-	$config['spam']['valid_inputs'][]='captcha';
-	$config['error']['securimage']=array(
-		'missing'=>'The captcha field was missing. Please try again',
-		'empty'=>'Please fill out the captcha',
-		'bad'=>'Incorrect or expired captcha',
-	);
+    $config['spam']['valid_inputs'][]='captcha';
+    $config['error']['securimage']=array(
+        'missing'=>'The captcha field was missing. Please try again',
+        'empty'=>'Please fill out the captcha',
+        'bad'=>'Incorrect or expired captcha',
+    );
 
     // Meta keywords. It's probably best to include these in per-board configurations.
     // $config['meta_keywords'] = 'chan,anonymous discussion,imageboard,tinyboard';
diff --git a/inc/context.php b/inc/context.php
new file mode 100644
index 00000000..137f6ebd
--- /dev/null
+++ b/inc/context.php
@@ -0,0 +1,38 @@
+<?php
+namespace Vichan;
+
+use Vichan\Data\Driver\CacheDriver;
+
+defined('TINYBOARD') or exit;
+
+
+class Context {
+	private array $definitions;
+
+	public function __construct(array $definitions) {
+		$this->definitions = $definitions;
+	}
+
+	public function get(string $name): mixed {
+		if (!isset($this->definitions[$name])) {
+			throw new \RuntimeException("Could not find a dependency named $name");
+		}
+
+		$ret = $this->definitions[$name];
+		if (is_callable($ret) && !is_string($ret) && !is_array($ret)) {
+			$ret = $ret($this);
+			$this->definitions[$name] = $ret;
+		}
+		return $ret;
+	}
+}
+
+function build_context(array $config): Context {
+	return new Context([
+		'config' => $config,
+		CacheDriver::class => function($c) {
+			// Use the global for backwards compatibility.
+			return \cache::getCache();
+		}
+	]);
+}
diff --git a/inc/mod/auth.php b/inc/mod/auth.php
index 958b7ba5..01b234a1 100644
--- a/inc/mod/auth.php
+++ b/inc/mod/auth.php
@@ -4,6 +4,7 @@
  *  Copyright (c) 2010-2013 Tinyboard Development Group
  */
 
+use Vichan\Context;
 use Vichan\Functions\Net;
 
 defined('TINYBOARD') or exit;
@@ -177,7 +178,7 @@ function make_secure_link_token($uri) {
 	return substr(sha1($config['cookies']['salt'] . '-' . $uri . '-' . $mod['id']), 0, 8);
 }
 
-function check_login($prompt = false) {
+function check_login(Context $ctx, $prompt = false) {
 	global $config, $mod;
 
 	// Validate session
@@ -187,7 +188,7 @@ function check_login($prompt = false) {
 		if (count($cookie) != 3) {
 			// Malformed cookies
 			destroyCookies();
-			if ($prompt) mod_login();
+			if ($prompt) mod_login($ctx);
 			exit;
 		}
 
@@ -200,7 +201,7 @@ function check_login($prompt = false) {
 		if ($cookie[1] !== mkhash($cookie[0], $user['password'], $cookie[2])) {
 			// Malformed cookies
 			destroyCookies();
-			if ($prompt) mod_login();
+			if ($prompt) mod_login($ctx);
 			exit;
 		}
 
diff --git a/inc/mod/pages.php b/inc/mod/pages.php
index b980c844..050e1216 100644
--- a/inc/mod/pages.php
+++ b/inc/mod/pages.php
@@ -1,9 +1,9 @@
 <?php
-
 /*
  *  Copyright (c) 2010-2013 Tinyboard Development Group
  */
-
+use Vichan\Context;
+use Vichan\Functions\Format;
 use Vichan\Functions\Net;
 
 use function Vichan\Functions\Net\decode_cursor;
@@ -45,7 +45,7 @@ function clone_wrapped_with_exist_check($clonefn, $src, $dest) {
     }
 }
 
-function mod_login($redirect = false) {
+function mod_login(Context $ctx, $redirect = false) {
     global $config;
 
     $args = [];
@@ -81,22 +81,22 @@ function mod_login($redirect = false) {
     mod_page(_('Login'), 'mod/login.html', $args);
 }
 
-function mod_confirm($request) {
-    $args = array('request' => $request, 'token' => make_secure_link_token($request));
+function mod_confirm(Context $ctx, $request) {
+    $args = [ 'request' => $request, 'token' => make_secure_link_token($request) ];
     if(isset($_GET['thread'])) {
         $args['rest'] = 'thread=' . $_GET['thread'];
     }
     mod_page(_('Confirm action'), 'mod/confirm.html', $args);
 }
 
-function mod_logout() {
+function mod_logout(Context $ctx) {
     global $config;
     destroyCookies();
 
     header('Location: ?/', true, $config['redirect_http']);
 }
 
-function mod_dashboard() {
+function mod_dashboard(Context $ctx) {
     global $config, $mod;
 
     $args = [];
@@ -190,7 +190,7 @@ function mod_dashboard() {
     mod_page(_('Dashboard'), 'mod/dashboard.html', $args);
 }
 
-function mod_search_redirect() {
+function mod_search_redirect(Context $ctx) {
     global $config;
 
     if (!hasPermission($config['mod']['search']))
@@ -213,7 +213,7 @@ function mod_search_redirect() {
     }
 }
 
-function mod_search($type, $search_query_escaped, $page_no = 1) {
+function mod_search(Context $ctx, $type, $search_query_escaped, $page_no = 1) {
     global $pdo, $config;
 
     if (!hasPermission($config['mod']['search']))
@@ -368,7 +368,7 @@ function mod_search($type, $search_query_escaped, $page_no = 1) {
     ));
 }
 
-function mod_edit_board($boardName) {
+function mod_edit_board(Context $ctx, $boardName) {
     global $board, $config;
 
     if (!openBoard($boardName))
@@ -470,7 +470,7 @@ function mod_edit_board($boardName) {
     }
 }
 
-function mod_new_board() {
+function mod_new_board(Context $ctx) {
     global $config, $board;
 
     if (!hasPermission($config['mod']['newboard']))
@@ -536,7 +536,7 @@ function mod_new_board() {
     mod_page(_('New board'), 'mod/board.html', array('new' => true, 'token' => make_secure_link_token('new-board')));
 }
 
-function mod_noticeboard($page_no = 1) {
+function mod_noticeboard(Context $ctx, $page_no = 1) {
     global $config, $pdo, $mod;
 
     if ($page_no < 1)
@@ -591,7 +591,7 @@ function mod_noticeboard($page_no = 1) {
     ));
 }
 
-function mod_noticeboard_delete($id) {
+function mod_noticeboard_delete(Context $ctx, $id) {
     global $config;
 
     if (!hasPermission($config['mod']['noticeboard_delete']))
@@ -609,7 +609,7 @@ function mod_noticeboard_delete($id) {
     header('Location: ?/noticeboard', true, $config['redirect_http']);
 }
 
-function mod_news($page_no = 1) {
+function mod_news(Context $ctx, $page_no = 1) {
     global $config, $pdo, $mod;
 
     if ($page_no < 1)
@@ -656,7 +656,7 @@ function mod_news($page_no = 1) {
     mod_page(_('News'), 'mod/news.html', array('news' => $news, 'count' => $count, 'token' => make_secure_link_token('edit_news')));
 }
 
-function mod_news_delete($id) {
+function mod_news_delete(Context $ctx, $id) {
     global $config;
 
     if (!hasPermission($config['mod']['news_delete']))
@@ -671,7 +671,7 @@ function mod_news_delete($id) {
     header('Location: ?/edit_news', true, $config['redirect_http']);
 }
 
-function mod_log($page_no = 1) {
+function mod_log(Context $ctx, $page_no = 1) {
     global $config;
 
     if ($page_no < 1)
@@ -696,7 +696,7 @@ function mod_log($page_no = 1) {
     mod_page(_('Moderation log'), 'mod/log.html', array('logs' => $logs, 'count' => $count));
 }
 
-function mod_user_log($username, $page_no = 1) {
+function mod_user_log(Context $ctx, $username, $page_no = 1) {
     global $config;
 
     if ($page_no < 1)
@@ -733,7 +733,7 @@ function protect_ip($entry) {
     return preg_replace(array($ipv4_link_regex, $ipv6_link_regex), "xxxx", $entry);
 }
 
-function mod_board_log($board, $page_no = 1, $hide_names = false, $public = false) {
+function mod_board_log(Context $ctx, $board, $page_no = 1, $hide_names = false, $public = false) {
     global $config;
 
     if ($page_no < 1)
@@ -766,8 +766,8 @@ function mod_board_log($board, $page_no = 1, $hide_names = false, $public = fals
     mod_page(_('Board log'), 'mod/log.html', array('logs' => $logs, 'count' => $count, 'board' => $board, 'hide_names' => $hide_names, 'public' => $public));
 }
 
-function mod_view_catalog($boardName) {
-    global $config, $mod;
+function mod_view_catalog(Context $ctx, $boardName) {
+	global $config;
     require_once($config['dir']['themes'].'/catalog/theme.php');
     $settings = [];
     $settings['boards'] = $boardName;
@@ -798,7 +798,7 @@ function mod_view_catalog($boardName) {
     }
 }
 
-function mod_view_board($boardName, $page_no = 1) {
+function mod_view_board(Context $ctx, $boardName, $page_no = 1) {
     global $config, $mod;
 
     if (!openBoard($boardName)){
@@ -829,7 +829,7 @@ function mod_view_board($boardName, $page_no = 1) {
     echo Element('index.html', $page);
 }
 
-function mod_view_thread($boardName, $thread) {
+function mod_view_thread(Context $ctx, $boardName, $thread) {
     global $config, $mod;
 
     if (!openBoard($boardName))
@@ -839,7 +839,7 @@ function mod_view_thread($boardName, $thread) {
     echo $page;
 }
 
-function mod_view_thread50($boardName, $thread) {
+function mod_view_thread50(Context $ctx, $boardName, $thread) {
     global $config, $mod;
 
     if (!openBoard($boardName))
@@ -849,8 +849,8 @@ function mod_view_thread50($boardName, $thread) {
     echo $page;
 }
 
-function mod_ip_remove_note($ip, $id) {
-    global $config, $mod;
+function mod_ip_remove_note(Context $ctx, $ip, $id) {
+    global $config;
 
     if (!hasPermission($config['mod']['remove_notes']))
             error($config['error']['noaccess']);
@@ -868,7 +868,7 @@ function mod_ip_remove_note($ip, $id) {
     header('Location: ?/IP/' . $ip . '#notes', true, $config['redirect_http']);
 }
 
-function mod_page_ip($ip, string $encoded_cursor = '') {
+function mod_ip(Context $ctx, $ip, string $encoded_cursor = '') {
     global $config, $mod;
 
     if (filter_var($ip, FILTER_VALIDATE_IP) === false)
@@ -1057,7 +1057,7 @@ function mod_page_ip($ip, string $encoded_cursor = '') {
     mod_page(sprintf('%s: %s', _('IP'), htmlspecialchars($ip)), 'mod/view_ip.html', $args, $args['hostname']);
 }
 
-function mod_ban() {
+function mod_ban(Context $ctx) {
     global $config;
 
     if (!hasPermission($config['mod']['ban']))
@@ -1078,7 +1078,7 @@ function mod_ban() {
         header('Location: ?/', true, $config['redirect_http']);
 }
 
-function mod_warning() {
+function mod_warning(Context $ctx) {
     global $config;
 
     if (!hasPermission($config['mod']['warning']))
@@ -1095,7 +1095,7 @@ function mod_warning() {
         header('Location: ?/', true, $config['redirect_http']);
 }
 
-function mod_bans() {
+function mod_bans(Context $ctx) {
     global $config;
     global $mod;
 
@@ -1130,7 +1130,7 @@ function mod_bans() {
     ));
 }
 
-function mod_bans_json() {
+function mod_bans_json(Context $ctx) {
         global $config, $mod;
 
         if (!hasPermission($config['mod']['ban']))
@@ -1142,7 +1142,7 @@ function mod_bans_json() {
     Bans::stream_json(false, false, !hasPermission($config['mod']['view_banstaff']), $mod['boards']);
 }
 
-function mod_ban_appeals() {
+function mod_ban_appeals(Context $ctx) {
     global $config, $board;
 
     if (!hasPermission($config['mod']['view_ban_appeals']))
@@ -1224,7 +1224,7 @@ function mod_ban_appeals() {
     ));
 }
 
-function mod_lock($board, $unlock, $post) {
+function mod_lock(Context $ctx, $board, $unlock, $post) {
     global $config;
 
     if (!openBoard($board))
@@ -1260,7 +1260,7 @@ function mod_lock($board, $unlock, $post) {
         event('lock', $post);
 }
 
-function mod_sticky($board, $unsticky, $post) {
+function mod_sticky(Context $ctx, $board, $unsticky, $post) {
     global $config;
 
     if (!openBoard($board))
@@ -1284,7 +1284,7 @@ function mod_sticky($board, $unsticky, $post) {
     header('Location: ?/' . sprintf($config['board_path'], $board) . $config['file_index'], true, $config['redirect_http']);
 }
 
-function mod_cycle($board, $uncycle, $post) {
+function mod_cycle(Context $ctx, $board, $uncycle, $post) {
     global $config;
 
     if (!openBoard($board))
@@ -1306,7 +1306,7 @@ function mod_cycle($board, $uncycle, $post) {
     header('Location: ?/' . sprintf($config['board_path'], $board) . $config['file_index'], true, $config['redirect_http']);
 }
 
-function mod_bumplock($board, $unbumplock, $post) {
+function mod_bumplock(Context $ctx, $board, $unbumplock, $post) {
     global $config;
 
     if (!openBoard($board))
@@ -1328,8 +1328,8 @@ function mod_bumplock($board, $unbumplock, $post) {
     header('Location: ?/' . sprintf($config['board_path'], $board) . $config['file_index'], true, $config['redirect_http']);
 }
 
-function mod_move_reply($originBoard, $postID) {
-    global $board, $config, $mod;
+function mod_move_reply(Context $ctx, $originBoard, $postID) {
+    global $board, $config;
 
     if (!openBoard($originBoard))
         error($config['error']['noboard']);
@@ -1432,8 +1432,8 @@ function mod_move_reply($originBoard, $postID) {
 
 }
 
-function mod_move($originBoard, $postID) {
-    global $board, $config, $mod, $pdo;
+function mod_move(Context $ctx, $originBoard, $postID) {
+    global $board, $config, $pdo;
 
     if (!openBoard($originBoard))
         error($config['error']['noboard']);
@@ -1645,8 +1645,8 @@ function mod_move($originBoard, $postID) {
     mod_page(_('Move thread'), 'mod/move.html', array('post' => $postID, 'board' => $originBoard, 'boards' => $boards, 'token' => $security_token));
 }
 
-function mod_merge($originBoard, $postID) {
-    global $board, $config, $mod, $pdo;
+function mod_merge(Context $ctx, $originBoard, $postID) {
+    global $board, $config, $pdo;
 
     if (!openBoard($originBoard))
         error($config['error']['noboard']);
@@ -1655,10 +1655,11 @@ function mod_merge($originBoard, $postID) {
         error($config['error']['noaccess']);
 
     $query = prepare(sprintf('SELECT * FROM ``posts_%s`` WHERE `id` = :id AND `thread` IS NULL', $originBoard));
-    $query->bindValue(':id', $postID);
+    $query->bindValue(':id', (int)$postID, \PDO::PARAM_INT);
     $query->execute() or error(db_error($query));
-    if (!$post = $query->fetch(PDO::FETCH_ASSOC))
+    if (!$post = $query->fetch(PDO::FETCH_ASSOC)) {
         error($config['error']['404']);
+    }
     $sourceOp = "";
     if ($post['thread']){
         $sourceOp = $post['thread'];
@@ -1886,7 +1887,7 @@ function mod_merge($originBoard, $postID) {
     mod_page(_('Merge thread'), 'mod/merge.html', array('post' => $postID, 'board' => $originBoard, 'boards' => $boards, 'token' => $security_token));
 }
 
-function mod_ban_post($board, $delete, $post, $token = false) {
+function mod_ban_post(Context $ctx, $board, $delete, $post, $token = false) {
     global $config, $mod;
 
     if (!openBoard($board))
@@ -1998,7 +1999,7 @@ function mod_ban_post($board, $delete, $post, $token = false) {
         'board' => $board,
         'delete' => (bool)$delete,
         'boards' => listBoards(),
-		'reasons' => $config['ban_reasons'],
+        'reasons' => $config['ban_reasons'],
         'token' => $security_token
     );
 
@@ -2009,7 +2010,7 @@ function mod_ban_post($board, $delete, $post, $token = false) {
     mod_page(_('New ban'), 'mod/ban_form.html', $args);
 }
 
-function mod_warning_post($board,$post, $token = false) {
+function mod_warning_post(Context $ctx, $board, $post, $token = false) {
     global $config, $mod;
 
     if (!openBoard($board))
@@ -2109,8 +2110,8 @@ function mod_warning_post($board,$post, $token = false) {
     mod_page(_('New warning'), 'mod/warning_form.html', $args);
 }
 
-function mod_edit_post($board, $edit_raw_html, $postID) {
-    global $config, $mod;
+function mod_edit_post(Context $ctx, $board, $edit_raw_html, $postID) {
+    global $config;
 
     if (!openBoard($board))
         error($config['error']['noboard']);
@@ -2186,8 +2187,8 @@ function mod_edit_post($board, $edit_raw_html, $postID) {
     }
 }
 
-function mod_delete($board, $post) {
-    global $config, $mod;
+function mod_delete(Context $ctx, $board, $post) {
+	global $config;
 
     if (!openBoard($board))
         error($config['error']['noboard']);
@@ -2252,8 +2253,8 @@ function mod_delete($board, $post) {
     }
 }
 
-function mod_deletefile($board, $post, $file) {
-    global $config, $mod;
+function mod_deletefile(Context $ctx, $board, $post, $file) {
+	global $config;
 
     if (!openBoard($board))
         error($config['error']['noboard']);
@@ -2275,8 +2276,8 @@ function mod_deletefile($board, $post, $file) {
     header('Location: ?/' . sprintf($config['board_path'], $board) . $config['file_index'], true, $config['redirect_http']);
 }
 
-function mod_spoiler_image($board, $post, $file) {
-    global $config, $mod;
+function mod_spoiler_image(Context $ctx, $board, $post, $file) {
+	global $config;
 
     if (!openBoard($board))
         error($config['error']['noboard']);
@@ -2320,8 +2321,8 @@ function mod_spoiler_image($board, $post, $file) {
     header('Location: ?/' . sprintf($config['board_path'], $board) . $config['file_index'], true, $config['redirect_http']);
 }
 
-function mod_deletebyip($boardName, $post, $global = false) {
-    global $config, $mod, $board;
+function mod_deletebyip(Context $ctx, $boardName, $post, $global = false) {
+	global $config, $board;
 
     $global = (bool)$global;
 
@@ -2442,7 +2443,7 @@ function mod_deletebyip($boardName, $post, $global = false) {
     header('Location: ?/' . sprintf($config['board_path'], $boardName) . $config['file_index'], true, $config['redirect_http']);
 }
 
-function mod_user($uid) {
+function mod_user(Context $ctx, $uid) {
     global $config, $mod;
 
     if (!hasPermission($config['mod']['editusers']) && !(hasPermission($config['mod']['change_password']) && $uid == $mod['id']))
@@ -2567,7 +2568,7 @@ function mod_user($uid) {
     ));
 }
 
-function mod_user_new() {
+function mod_user_new(Context $ctx) {
     global $pdo, $config;
 
     if (!hasPermission($config['mod']['createusers']))
@@ -2620,7 +2621,7 @@ function mod_user_new() {
 }
 
 
-function mod_users() {
+function mod_users(Context $ctx) {
     global $config;
 
     if (!hasPermission($config['mod']['manageusers']))
@@ -2641,7 +2642,7 @@ function mod_users() {
     mod_page(sprintf('%s (%d)', _('Manage users'), count($users)), 'mod/users.html', array('users' => $users));
 }
 
-function mod_user_promote($uid, $action) {
+function mod_user_promote(Context $ctx, $uid, $action) {
     global $config;
 
     if (!hasPermission($config['mod']['promoteusers']))
@@ -2684,7 +2685,7 @@ function mod_user_promote($uid, $action) {
     header('Location: ?/users', true, $config['redirect_http']);
 }
 
-function mod_pm($id, $reply = false) {
+function mod_pm(Context $ctx, $id, $reply = false) {
     global $mod, $config;
 
     if ($reply && !hasPermission($config['mod']['create_pm']))
@@ -2739,7 +2740,7 @@ function mod_pm($id, $reply = false) {
     }
 }
 
-function mod_inbox() {
+function mod_inbox(Context $ctx) {
     global $config, $mod;
 
     $query = prepare('SELECT `unread`,``pms``.`id`, `time`, `sender`, `to`, `message`, `username` FROM ``pms`` LEFT JOIN ``mods`` ON ``mods``.`id` = `sender` WHERE `to` = :mod ORDER BY `unread` DESC, `time` DESC');
@@ -2763,7 +2764,7 @@ function mod_inbox() {
 }
 
 
-function mod_new_pm($username) {
+function mod_new_pm(Context $ctx, $username) {
     global $config, $mod;
 
     if (!hasPermission($config['mod']['create_pm']))
@@ -2811,7 +2812,7 @@ function mod_new_pm($username) {
     ));
 }
 
-function mod_rebuild() {
+function mod_rebuild(Context $ctx) {
     global $config, $twig;
 
     if (!hasPermission($config['mod']['rebuild']))
@@ -2883,7 +2884,7 @@ function mod_rebuild() {
     ));
 }
 
-function mod_reports() {
+function mod_reports(Context $ctx) {
     global $config, $mod;
 
     if (!hasPermission($config['mod']['reports']))
@@ -2987,7 +2988,7 @@ function mod_reports() {
     );
 }
 
-function mod_report_dismiss($id, $all = false) {
+function mod_report_dismiss(Context $ctx, $id, $all = false) {
     global $config;
 
     $query = prepare("SELECT `post`, `board`, `ip` FROM ``reports`` WHERE `id` = :id");
@@ -3024,7 +3025,7 @@ function mod_report_dismiss($id, $all = false) {
     header('Location: ?/reports', true, $config['redirect_http']);
 }
 
-function mod_recent_posts($lim,$board_list = false,$json=false) {
+function mod_recent_posts(Context $ctx, $lim, $board_list = false, $json = false) {
     global $config, $mod, $pdo;
 
     if (!hasPermission($config['mod']['recent']))
@@ -3122,7 +3123,7 @@ function mod_recent_posts($lim,$board_list = false,$json=false) {
     }
 }
 
-function mod_config($board_config = false) {
+function mod_config(Context $ctx, $board_config = false) {
     global $config, $mod, $board;
 
     if ($board_config && !openBoard($board_config))
@@ -3262,7 +3263,7 @@ function mod_config($board_config = false) {
     ));
 }
 
-function mod_themes_list() {
+function mod_themes_list(Context $ctx) {
     global $config;
 
     if (!hasPermission($config['mod']['themes']))
@@ -3296,7 +3297,7 @@ function mod_themes_list() {
     ));
 }
 
-function mod_theme_configure($theme_name) {
+function mod_theme_configure(Context $ctx, $theme_name) {
     global $config;
 
     if (!hasPermission($config['mod']['themes']))
@@ -3378,7 +3379,7 @@ function mod_theme_configure($theme_name) {
     ));
 }
 
-function mod_theme_uninstall($theme_name) {
+function mod_theme_uninstall(Context $ctx, $theme_name) {
     global $config;
 
     if (!hasPermission($config['mod']['themes']))
@@ -3395,7 +3396,7 @@ function mod_theme_uninstall($theme_name) {
     header('Location: ?/themes', true, $config['redirect_http']);
 }
 
-function mod_theme_rebuild($theme_name) {
+function mod_theme_rebuild(Context $ctx, $theme_name) {
     global $config;
 
     if (!hasPermission($config['mod']['themes']))
@@ -3436,15 +3437,15 @@ function delete_page_base($page = '', $board = false) {
     header('Location: ?/edit_pages' . ($board ? ('/' . $board) : ''), true, $config['redirect_http']);
 }
 
-function mod_delete_page($page = '') {
-    delete_page_base($page);
+function mod_delete_page(Context $ctx, $page = '') {
+	delete_page_base($ctx, $page);
 }
 
-function mod_delete_page_board($page = '', $board = false) {
-    delete_page_base($page, $board);
+function mod_delete_page_board(Context $ctx, $page = '', $board = false) {
+	delete_page_base($ctx, $page, $board);
 }
 
-function mod_edit_page($id) {
+function mod_edit_page(Context $ctx, $id) {
     global $config, $mod, $board;
 
     $query = prepare('SELECT * FROM ``pages`` WHERE `id` = :id');
@@ -3515,7 +3516,7 @@ function mod_edit_page($id) {
     mod_page(sprintf(_('Editing static page: %s'), $page['name']), 'mod/edit_page.html', array('page' => $page, 'token' => make_secure_link_token("edit_page/$id"), 'content' => prettify_textarea($content), 'board' => $board));
 }
 
-function mod_pages($board = false) {
+function mod_pages(Context $ctx, $board = false) {
     global $config, $mod, $pdo;
 
     if (empty($board))
@@ -3569,7 +3570,7 @@ function mod_pages($board = false) {
     mod_page(_('Pages'), 'mod/pages.html', array('pages' => $pages, 'token' => make_secure_link_token('edit_pages' . ($board ? ('/' . $board) : '')), 'board' => $board));
 }
 
-function mod_debug_antispam() {
+function mod_debug_antispam(Context $ctx) {
     global $pdo, $config;
 
     $args = [];
@@ -3606,7 +3607,7 @@ function mod_debug_antispam() {
     mod_page(_('Debug: Anti-spam'), 'mod/debug/antispam.html', $args);
 }
 
-function mod_debug_recent_posts() {
+function mod_debug_recent_posts(Context $ctx) {
     global $pdo, $config;
 
     $limit = 500;
@@ -3640,7 +3641,7 @@ function mod_debug_recent_posts() {
     mod_page(_('Debug: Recent posts'), 'mod/debug/recent_posts.html', array('posts' => $posts, 'flood_posts' => $flood_posts));
 }
 
-function mod_debug_sql() {
+function mod_debug_sql(Context $ctx) {
     global $config;
 
     if (!hasPermission($config['mod']['debug_sql']))
@@ -3663,25 +3664,3 @@ function mod_debug_sql() {
 
     mod_page(_('Debug: SQL'), 'mod/debug/sql.html', $args);
 }
-
-function mod_debug_apc() {
-    global $config;
-
-    if (!hasPermission($config['mod']['debug_apc']))
-        error($config['error']['noaccess']);
-
-    if ($config['cache']['enabled'] != 'apc')
-        error('APC is not enabled.');
-
-    $cache_info = apc_cache_info('user');
-
-    // $cached_vars = new APCIterator('user', '/^' . $config['cache']['prefix'] . '/');
-    $cached_vars = [];
-    foreach ($cache_info['cache_list'] as $var) {
-        if ($config['cache']['prefix'] != '' && strpos(isset($var['key']) ? $var['key'] : $var['info'], $config['cache']['prefix']) !== 0)
-            continue;
-        $cached_vars[] = $var;
-    }
-
-    mod_page(_('Debug: APC'), 'mod/debug/apc.html', array('cached_vars' => $cached_vars));
-}
diff --git a/inc/polyfill.php b/inc/polyfill.php
index 2b14c4dc..4368c8e8 100644
--- a/inc/polyfill.php
+++ b/inc/polyfill.php
@@ -1,187 +1,10 @@
 <?php
 
-// PHP 5.4
+// PHP 8.0
 
-if (!function_exists('hex2bin')) {
-	function hex2bin($data) {
-		return pack("H*" , $hex_string);
-	}
-}
-
-// PHP 5.6
-
-if (!function_exists('hash_equals')) {
-	function hash_equals($ours, $theirs) {
-		$ours = (string)$ours;
-		$theirs = (string)$theirs;
-
-		$tlen = strlen($theirs);
-		$olen = strlen($ours);
-
-		$answer = 0;
-		for ($i = 0; $i < $tlen; $i++) {
-			$answer |= ord($ours[$olen > $i ? $i : 0]) ^ ord($theirs[$i]);
-		}
-
-		return $answer === 0 && $olen === $tlen;
-	}
-}
-
-if (!function_exists('imagecreatefrombmp')) {
-	/*********************************************/
-	/* Fonction: imagecreatefrombmp              */
-	/* Author:   DHKold                          */
-	/* Contact:  admin@dhkold.com                */
-	/* Date:     The 15th of June 2005           */
-	/* Version:  2.0B                            */
-	/*********************************************/
-	function imagecreatefrombmp($filename) {
-		if (! $f1 = fopen($filename,"rb")) return FALSE;
-		$FILE = unpack("vfile_type/Vfile_size/Vreserved/Vbitmap_offset", fread($f1,14));
-		if ($FILE['file_type'] != 19778) return FALSE;
-		$BMP = unpack('Vheader_size/Vwidth/Vheight/vplanes/vbits_per_pixel'.
-						'/Vcompression/Vsize_bitmap/Vhoriz_resolution'.
-						'/Vvert_resolution/Vcolors_used/Vcolors_important', fread($f1,40));
-		$BMP['colors'] = pow(2,$BMP['bits_per_pixel']);
-		if ($BMP['size_bitmap'] == 0) $BMP['size_bitmap'] = $FILE['file_size'] - $FILE['bitmap_offset'];
-		$BMP['bytes_per_pixel'] = $BMP['bits_per_pixel']/8;
-		$BMP['bytes_per_pixel2'] = ceil($BMP['bytes_per_pixel']);
-		$BMP['decal'] = ($BMP['width']*$BMP['bytes_per_pixel']/4);
-		$BMP['decal'] -= floor($BMP['width']*$BMP['bytes_per_pixel']/4);
-		$BMP['decal'] = 4-(4*$BMP['decal']);
-		if ($BMP['decal'] == 4) $BMP['decal'] = 0;
-		$PALETTE = array();
-		if ($BMP['colors'] < 16777216)
-		{
-			$PALETTE = unpack('V'.$BMP['colors'], fread($f1,$BMP['colors']*4));
-		}
-		$IMG = fread($f1,$BMP['size_bitmap']);
-		$VIDE = chr(0);
-		$res = imagecreatetruecolor($BMP['width'],$BMP['height']);
-		$P = 0;
-		$Y = $BMP['height']-1;
-		while ($Y >= 0)
-		{
-			$X=0;
-			while ($X < $BMP['width'])
-			{
-			if ($BMP['bits_per_pixel'] == 24)
-				$COLOR = unpack("V",substr($IMG,$P,3).$VIDE);
-			elseif ($BMP['bits_per_pixel'] == 16)
-			{  
-				$COLOR = unpack("n",substr($IMG,$P,2));
-				$COLOR[1] = $PALETTE[$COLOR[1]+1];
-			}
-			elseif ($BMP['bits_per_pixel'] == 8)
-			{  
-				$COLOR = unpack("n",$VIDE.substr($IMG,$P,1));
-				$COLOR[1] = $PALETTE[$COLOR[1]+1];
-			}
-			elseif ($BMP['bits_per_pixel'] == 4)
-			{
-				$COLOR = unpack("n",$VIDE.substr($IMG,floor($P),1));
-				if (($P*2)%2 == 0) $COLOR[1] = ($COLOR[1] >> 4) ; else $COLOR[1] = ($COLOR[1] & 0x0F);
-				$COLOR[1] = $PALETTE[$COLOR[1]+1];
-			}
-			elseif ($BMP['bits_per_pixel'] == 1)
-			{
-				$COLOR = unpack("n",$VIDE.substr($IMG,floor($P),1));
-				if     (($P*8)%8 == 0) $COLOR[1] =  $COLOR[1]        >>7;
-				elseif (($P*8)%8 == 1) $COLOR[1] = ($COLOR[1] & 0x40)>>6;
-				elseif (($P*8)%8 == 2) $COLOR[1] = ($COLOR[1] & 0x20)>>5;
-				elseif (($P*8)%8 == 3) $COLOR[1] = ($COLOR[1] & 0x10)>>4;
-				elseif (($P*8)%8 == 4) $COLOR[1] = ($COLOR[1] & 0x8)>>3;
-				elseif (($P*8)%8 == 5) $COLOR[1] = ($COLOR[1] & 0x4)>>2;
-				elseif (($P*8)%8 == 6) $COLOR[1] = ($COLOR[1] & 0x2)>>1;
-				elseif (($P*8)%8 == 7) $COLOR[1] = ($COLOR[1] & 0x1);
-				$COLOR[1] = $PALETTE[$COLOR[1]+1];
-			}
-			else
-				return FALSE;
-			imagesetpixel($res,$X,$Y,$COLOR[1]);
-			$X++;
-			$P += $BMP['bytes_per_pixel'];
-			}
-			$Y--;
-			$P+=$BMP['decal'];
-		}
-		fclose($f1);
-		return $res;
-	}
-}
-
-if (!function_exists('imagebmp')) {
-	function imagebmp(&$img, $filename='') {
-		$widthOrig = imagesx($img);
-		$widthFloor = ((floor($widthOrig/16))*16);
-		$widthCeil = ((ceil($widthOrig/16))*16);
-		$height = imagesy($img);
-		$size = ($widthCeil*$height*3)+54;
-		// Bitmap File Header
-		$result = 'BM';	 // header (2b)
-		$result .= int_to_dword($size); // size of file (4b)
-		$result .= int_to_dword(0); // reserved (4b)
-		$result .= int_to_dword(54); // byte location in the file which is first byte of IMAGE (4b)
-		// Bitmap Info Header
-		$result .= int_to_dword(40); // Size of BITMAPINFOHEADER (4b)
-		$result .= int_to_dword($widthCeil); // width of bitmap (4b)
-		$result .= int_to_dword($height); // height of bitmap (4b)
-		$result .= int_to_word(1);	// biPlanes = 1 (2b)
-		$result .= int_to_word(24); // biBitCount = {1 (mono) or 4 (16 clr ) or 8 (256 clr) or 24 (16 Mil)} (2b
-		$result .= int_to_dword(0); // RLE COMPRESSION (4b)
-		$result .= int_to_dword(0); // width x height (4b)
-		$result .= int_to_dword(0); // biXPelsPerMeter (4b)
-		$result .= int_to_dword(0); // biYPelsPerMeter (4b)
-		$result .= int_to_dword(0); // Number of palettes used (4b)
-		$result .= int_to_dword(0); // Number of important colour (4b)
-		// is faster than chr()
-		$arrChr = array();
-		for ($i=0; $i<256; $i++){
-		$arrChr[$i] = chr($i);
-		}
-		// creates image data
-		$bgfillcolor = array('red'=>0, 'green'=>0, 'blue'=>0);
-		// bottom to top - left to right - attention blue green red !!!
-		$y=$height-1;
-		for ($y2=0; $y2<$height; $y2++) {
-			for ($x=0; $x<$widthFloor;	) {
-				$rgb = imagecolorsforindex($img, imagecolorat($img, $x++, $y));
-				$result .= $arrChr[$rgb['blue']].$arrChr[$rgb['green']].$arrChr[$rgb['red']];
-				$rgb = imagecolorsforindex($img, imagecolorat($img, $x++, $y));
-				$result .= $arrChr[$rgb['blue']].$arrChr[$rgb['green']].$arrChr[$rgb['red']];
-				$rgb = imagecolorsforindex($img, imagecolorat($img, $x++, $y));
-				$result .= $arrChr[$rgb['blue']].$arrChr[$rgb['green']].$arrChr[$rgb['red']];
-				$rgb = imagecolorsforindex($img, imagecolorat($img, $x++, $y));
-				$result .= $arrChr[$rgb['blue']].$arrChr[$rgb['green']].$arrChr[$rgb['red']];
-				$rgb = imagecolorsforindex($img, imagecolorat($img, $x++, $y));
-				$result .= $arrChr[$rgb['blue']].$arrChr[$rgb['green']].$arrChr[$rgb['red']];
-				$rgb = imagecolorsforindex($img, imagecolorat($img, $x++, $y));
-				$result .= $arrChr[$rgb['blue']].$arrChr[$rgb['green']].$arrChr[$rgb['red']];
-				$rgb = imagecolorsforindex($img, imagecolorat($img, $x++, $y));
-				$result .= $arrChr[$rgb['blue']].$arrChr[$rgb['green']].$arrChr[$rgb['red']];
-				$rgb = imagecolorsforindex($img, imagecolorat($img, $x++, $y));
-				$result .= $arrChr[$rgb['blue']].$arrChr[$rgb['green']].$arrChr[$rgb['red']];
-			}
-			for ($x=$widthFloor; $x<$widthCeil; $x++) {
-				$rgb = ($x<$widthOrig) ? imagecolorsforindex($img, imagecolorat($img, $x, $y)) : $bgfillcolor;
-				$result .= $arrChr[$rgb['blue']].$arrChr[$rgb['green']].$arrChr[$rgb['red']];
-			}
-			$y--;
-		}
-		// see imagegif
-		if ($filename == '') {
-			echo $result;
-		} else {
-			$file = fopen($filename, 'wb');
-			fwrite($file, $result);
-			fclose($file);
-		}
-	}
-	// imagebmp helpers
-	function int_to_dword($n) {
-		return chr($n & 255).chr(($n >> 8) & 255).chr(($n >> 16) & 255).chr(($n >> 24) & 255);
-	}
-	function int_to_word($n) {
-		return chr($n & 255).chr(($n >> 8) & 255);
+if (!function_exists('str_starts_with')) {
+	function str_starts_with(string $haystack, string $needle): bool {
+		// https://wiki.php.net/rfc/add_str_starts_with_and_ends_with_functions#str_starts_with
+		return \strncmp($haystack, $needle, \strlen($needle)) === 0;
 	}
 }
diff --git a/mod.php b/mod.php
index 9587c8e1..bb260251 100644
--- a/mod.php
+++ b/mod.php
@@ -1,18 +1,21 @@
 <?php
-
 /*
  *  Copyright (c) 2010-2014 Tinyboard Development Group
  */
 
 require_once 'inc/bootstrap.php';
 
-if ($config['debug'])
+if ($config['debug']) {
 	$parse_start_time = microtime(true);
+}
 
 require_once 'inc/bans.php';
 require_once 'inc/mod/pages.php';
 
-check_login(true);
+
+$ctx = Vichan\build_context($config);
+
+check_login($ctx, true);
 
 $query = isset($_SERVER['QUERY_STRING']) ? rawurldecode($_SERVER['QUERY_STRING']) : '';
 
@@ -22,7 +25,7 @@ if(isset($_GET['thread'])) {
     $query = explode("&thread=", $query)[0];
 }
 
-$pages = array(
+$pages = [
 	''					=> ':?/',			// redirect to dashboard
 	'/'					=> 'dashboard',			// dashboard
 	'/confirm/(.+)'				=> 'confirm',			// confirm action (if javascript didn't work)
@@ -107,7 +110,6 @@ $pages = array(
 	// these pages aren't listed in the dashboard without $config['debug']
 	'/debug/antispam'			=> 'debug_antispam',
 	'/debug/recent'				=> 'debug_recent_posts',
-	'/debug/apc'				=> 'debug_apc',
 	'/debug/sql'				=> 'secure_POST debug_sql',
 
 	// This should always be at the end:
@@ -121,14 +123,14 @@ $pages = array(
 			str_replace('%d', '(\d+)', preg_quote($config['file_page'], '!'))	=> 'view_thread',
 
 	'/(\%b)/' . preg_quote($config['dir']['res'], '!') .
-			str_replace(array('%d','%s'), array('(\d+)', '[a-z0-9-]+'), preg_quote($config['file_page50_slug'], '!'))	=> 'view_thread50',
+			str_replace([ '%d','%s' ], [ '(\d+)', '[a-z0-9-]+' ], preg_quote($config['file_page50_slug'], '!'))	=> 'view_thread50',
 	'/(\%b)/' . preg_quote($config['dir']['res'], '!') .
-			str_replace(array('%d','%s'), array('(\d+)', '[a-z0-9-]+'), preg_quote($config['file_page_slug'], '!'))	=> 'view_thread',
-);
+			str_replace([ '%d','%s' ], [ '(\d+)', '[a-z0-9-]+' ], preg_quote($config['file_page_slug'], '!'))	=> 'view_thread',
+];
 
 
 if (!$mod) {
-	$pages = array('!^(.+)?$!' => 'login');
+	$pages = [ '!^(.+)?$!' => 'login' ];
 } elseif (isset($_GET['status'], $_GET['r'])) {
 	header('Location: ' . $_GET['r'], true, (int)$_GET['status']);
 	exit;
@@ -138,12 +140,11 @@ if (isset($config['mod']['custom_pages'])) {
 	$pages = array_merge($pages, $config['mod']['custom_pages']);
 }
 
-$new_pages = array();
+$new_pages = [];
 foreach ($pages as $key => $callback) {
 	if (is_string($callback) && preg_match('/^secure /', $callback)) {
 		$key .= '(/(?P<token>[a-f0-9]{8}))?';
-    }
-
+	}
 	$key = str_replace('\%b', '?P<board>' . sprintf(substr($config['board_path'], 0, -1), $config['board_regex']), $key);
 	$new_pages[@$key[0] == '!' ? $key : '!^' . $key . '(?:&[^&=]+=[^&]*)*$!u'] = $callback;
 }
@@ -151,7 +152,7 @@ $pages = $new_pages;
 
 foreach ($pages as $uri => $handler) {
 	if (preg_match($uri, $query, $matches)) {
-		$matches = array_slice($matches, 1);
+		$matches[0] = $ctx; // Replace the text captured by the full pattern with a reference to the context.
 
 		if (isset($matches['board'])) {
 			$board_match = $matches['board'];
@@ -171,7 +172,7 @@ foreach ($pages as $uri => $handler) {
 					if ($secure_post_only)
 						error($config['error']['csrf']);
 					else {
-						mod_confirm(substr($query, 1));
+						mod_confirm($ctx, substr($query, 1));
 						exit;
 					}
 				}
@@ -186,24 +187,20 @@ foreach ($pages as $uri => $handler) {
 		}
 
 		if ($config['debug']) {
-			$debug['mod_page'] = array(
+			$debug['mod_page'] = [
 				'req' => $query,
 				'match' => $uri,
 				'handler' => $handler,
-			);
+			];
 			$debug['time']['parse_mod_req'] = '~' . round((microtime(true) - $parse_start_time) * 1000, 2) . 'ms';
 		}
 
-		if (is_array($matches)) {
-			// we don't want to call named parameters (PHP 8)
-			$matches = array_values($matches);
-		}
+		// We don't want to call named parameters (PHP 8).
+		$matches = array_values($matches);
 
 		if (is_string($handler)) {
 			if ($handler[0] == ':') {
 				header('Location: ' . substr($handler, 1),  true, $config['redirect_http']);
-			} elseif (is_callable("mod_page_$handler")) {
-				call_user_func_array("mod_page_$handler", $matches);
 			} elseif (is_callable("mod_$handler")) {
 				call_user_func_array("mod_$handler", $matches);
 			} else {
diff --git a/post.php b/post.php
index 9a2a219b..78a1bb90 100644
--- a/post.php
+++ b/post.php
@@ -3,6 +3,8 @@
  *  Copyright (c) 2010-2014 Tinyboard Development Group
  */
 
+use Vichan\Context;
+
 require_once 'inc/bootstrap.php';
 
 /**
@@ -529,7 +531,7 @@ function handle_nntpchan()
     );
 }
 
-function handle_delete()
+function handle_delete(Context $ctx)
 {
     // Delete
     global $config, $board, $mod;
@@ -537,7 +539,7 @@ function handle_delete()
         error($config['error']['bot']);
     }
 
-    check_login(false);
+    check_login($ctx, false);
     $is_mod = !!$mod;
 
     if (isset($_POST['mod']) && $_POST['mod'] && !$mod) {
@@ -653,7 +655,7 @@ function handle_delete()
     rebuildThemes('post-delete', $board['uri']);
 }
 
-function handle_report()
+function handle_report(Context $ctx)
 {
     global $config, $board;
     if (!isset($_POST['board'], $_POST['reason']))
@@ -802,7 +804,7 @@ function handle_report()
     }
 }
 
-function handle_post()
+function handle_post(Context $ctx)
 {
     global $config, $dropped_post, $board, $mod, $pdo;
 
@@ -911,7 +913,7 @@ function handle_post()
         }
 
         if ($post['mod'] = isset($_POST['mod']) && $_POST['mod']) {
-            check_login(false);
+            check_login($ctx, false);
             if (!$mod) {
                 // Liar. You're not a mod >:-[
                 error($config['error']['notamod']);
@@ -1846,7 +1848,7 @@ function handle_post()
     }
 }
 
-function handle_appeal()
+function handle_appeal(Context $ctx)
 {
     global $config;
     if (!isset($_POST['ban_id'])) {
@@ -1899,14 +1901,16 @@ if (isset($_GET['Newsgroups'])) {
     }
 }
 
+$ctx = Vichan\build_context($config);
+
 if (isset($_POST['delete'])) {
-    handle_delete();
+    handle_delete($ctx);
 } elseif (isset($_POST['report'])) {
-    handle_report();
+    handle_report($ctx);
 } elseif (isset($_POST['post']) || $dropped_post) {
-    handle_post();
+    handle_post($ctx);
 } elseif (isset($_POST['appeal'])) {
-    handle_appeal();
+    handle_appeal($ctx);
 } else {
     if (!file_exists($config['has_installed'])) {
         header('Location: install.php', true, $config['redirect_http']);
diff --git a/tools/maintenance.php b/tools/maintenance.php
index 734d2d45..075fe5ce 100644
--- a/tools/maintenance.php
+++ b/tools/maintenance.php
@@ -87,5 +87,20 @@ echo "Deleted $deleted_count invalid reports in $delta seconds!\n";
 $time_tot += $delta;
 $deleted_tot += $deleted_count;
 
+if ($config['cache']['enabled'] === 'fs') {
+	$fs_cache = new Vichan\Data\Driver\FsCacheDriver(
+		$config['cache']['prefix'],
+		"tmp/cache/{$config['cache']['prefix']}",
+		'.lock',
+		false
+	);
+	$start = microtime(true);
+	$fs_cache->collect();
+	$delta = microtime(true) - $start;
+	echo "Deleted $deleted_count expired filesystem cache items in $delta seconds!\n";
+	$time_tot = $delta;
+	$deleted_tot = $deleted_count;
+}
+
 $time_tot = number_format((float)$time_tot, 4, '.', '');
 modLog("Deleted $deleted_tot expired entries in {$time_tot}s with maintenance tool");