diff --git a/inc/Data/Driver/ErrorLogLogDriver.php b/inc/Data/Driver/ErrorLogLogDriver.php
new file mode 100644
index 00000000..e2050606
--- /dev/null
+++ b/inc/Data/Driver/ErrorLogLogDriver.php
@@ -0,0 +1,28 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+/**
+ * Log via the php function error_log.
+ */
+class ErrorLogLogDriver implements LogDriver {
+	use LogTrait;
+
+	private string $name;
+	private int $level;
+
+	public function __construct(string $name, int $level) {
+		$this->name = $name;
+		$this->level = $level;
+	}
+
+	public function log(int $level, string $message): void {
+		if ($level <= $this->level) {
+			$lv = $this->levelToString($level);
+			$line = "{$this->name} $lv: $message";
+			\error_log($line, 0, null, null);
+		}
+	}
+}
diff --git a/inc/Data/Driver/FileLogDriver.php b/inc/Data/Driver/FileLogDriver.php
new file mode 100644
index 00000000..18423cf1
--- /dev/null
+++ b/inc/Data/Driver/FileLogDriver.php
@@ -0,0 +1,60 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+/**
+ * Log to a file.
+ */
+class FileLogDriver implements LogDriver {
+	use LogTrait;
+
+	private string $name;
+	private int $level;
+	private mixed $fd;
+
+	public function __construct(string $name, int $level, string $file_path) {
+		/*
+		 * error_log is slow as hell in it's 3rd mode, so use fopen + file locking instead.
+		 * https://grobmeier.solutions/performance-ofnonblocking-write-to-files-via-php-21082009.html
+		 *
+		 * Whatever file appending is atomic is contentious:
+		 *  - There are no POSIX guarantees: https://stackoverflow.com/a/7237901
+		 *  - But linus suggested they are on linux, on some filesystems: https://web.archive.org/web/20151201111541/http://article.gmane.org/gmane.linux.kernel/43445
+		 *  - But it doesn't seem to be always the case: https://www.notthewizard.com/2014/06/17/are-files-appends-really-atomic/
+		 *
+		 * So we just use file locking to be sure.
+		 */
+
+		$this->fd = \fopen($file_path, 'a');
+		if ($this->fd === false) {
+			throw new \RuntimeException("Unable to open log file at $file_path");
+		}
+
+		$this->name = $name;
+		$this->level = $level;
+
+		// In some cases PHP does not run the destructor.
+		\register_shutdown_function([$this, 'close']);
+	}
+
+	public function __destruct() {
+		$this->close();
+	}
+
+	public function log(int $level, string $message): void {
+		if ($level <= $this->level) {
+			$lv = $this->levelToString($level);
+			$line = "{$this->name} $lv: $message\n";
+			\flock($this->fd, LOCK_EX);
+			\fwrite($this->fd, $line);
+			\flock($this->fd, LOCK_UN);
+		}
+	}
+
+	public function close() {
+		\flock($this->fd, LOCK_UN);
+		\fclose($this->fd);
+	}
+}
diff --git a/inc/Data/Driver/LogDriver.php b/inc/Data/Driver/LogDriver.php
new file mode 100644
index 00000000..fddc3f27
--- /dev/null
+++ b/inc/Data/Driver/LogDriver.php
@@ -0,0 +1,22 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+interface LogDriver {
+	public const EMERG = \LOG_EMERG;
+	public const ERROR = \LOG_ERR;
+	public const WARNING = \LOG_WARNING;
+	public const NOTICE = \LOG_NOTICE;
+	public const INFO = \LOG_INFO;
+	public const DEBUG = \LOG_DEBUG;
+
+	/**
+	 * Log a message if the level of relevancy is at least the minimum.
+	 *
+	 * @param int $level Message level. Use Log interface constants.
+	 * @param string $message The message to log.
+	 */
+	public function log(int $level, string $message): void;
+}
diff --git a/inc/Data/Driver/LogTrait.php b/inc/Data/Driver/LogTrait.php
new file mode 100644
index 00000000..0664d5c4
--- /dev/null
+++ b/inc/Data/Driver/LogTrait.php
@@ -0,0 +1,26 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+trait LogTrait {
+	public static function levelToString(int $level): string {
+		switch ($level) {
+			case LogDriver::EMERG:
+				return 'EMERG';
+			case LogDriver::ERROR:
+				return 'ERROR';
+			case LogDriver::WARNING:
+				return 'WARNING';
+			case LogDriver::NOTICE:
+				return 'NOTICE';
+			case LogDriver::INFO:
+				return 'INFO';
+			case LogDriver::DEBUG:
+				return 'DEBUG';
+			default:
+				throw new \InvalidArgumentException('Not a logging level');
+		}
+	}
+}
diff --git a/inc/Data/Driver/StderrLogDriver.php b/inc/Data/Driver/StderrLogDriver.php
new file mode 100644
index 00000000..4c766033
--- /dev/null
+++ b/inc/Data/Driver/StderrLogDriver.php
@@ -0,0 +1,27 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+/**
+ * Log to php's standard error file stream.
+ */
+class StderrLogDriver implements LogDriver {
+	use LogTrait;
+
+	private string $name;
+	private int $level;
+
+	public function __construct(string $name, int $level) {
+		$this->name = $name;
+		$this->level = $level;
+	}
+
+	public function log(int $level, string $message): void {
+		if ($level <= $this->level) {
+			$lv = $this->levelToString($level);
+			\fwrite(\STDERR, "{$this->name} $lv: $message\n");
+		}
+	}
+}
diff --git a/inc/Data/Driver/SyslogLogDriver.php b/inc/Data/Driver/SyslogLogDriver.php
new file mode 100644
index 00000000..c0df5304
--- /dev/null
+++ b/inc/Data/Driver/SyslogLogDriver.php
@@ -0,0 +1,35 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+/**
+ * Log to syslog.
+ */
+class SyslogLogDriver implements LogDriver {
+	private int $level;
+
+	public function __construct(string $name, int $level, bool $print_stderr) {
+		$flags = \LOG_ODELAY;
+		if ($print_stderr) {
+			$flags |= \LOG_PERROR;
+		}
+
+		if (!\openlog($name, $flags, \LOG_USER)) {
+			throw new \RuntimeException('Unable to open syslog');
+		}
+
+		$this->level = $level;
+	}
+
+	public function log(int $level, string $message): void {
+		if ($level <= $this->level) {
+			if (isset($_SERVER['REMOTE_ADDR'], $_SERVER['REQUEST_METHOD'], $_SERVER['REQUEST_URI'])) {
+				// CGI
+				\syslog($level, "$message - client: {$_SERVER['REMOTE_ADDR']}, request: \"{$_SERVER['REQUEST_METHOD']} {$_SERVER['REQUEST_URI']}\"");
+			} else {
+				\syslog($level, $message);
+			}
+		}
+	}
+}