diff --git a/src/main/php/web/Application.class.php b/src/main/php/web/Application.class.php
index ed5a92dc..3b0c2b05 100755
--- a/src/main/php/web/Application.class.php
+++ b/src/main/php/web/Application.class.php
@@ -6,7 +6,7 @@
  * @test  xp://web.unittest.ApplicationTest
  */
 abstract class Application implements \lang\Value {
-  private $routing;
+  private $routing= null;
   protected $environment;
 
   /**
diff --git a/src/main/php/web/Environment.class.php b/src/main/php/web/Environment.class.php
index 540b1aa1..0ea41cd2 100755
--- a/src/main/php/web/Environment.class.php
+++ b/src/main/php/web/Environment.class.php
@@ -15,7 +15,7 @@
  * @test  xp://web.unittest.EnvironmentTest
  */
 class Environment {
-  private $profile, $webroot, $docroot, $arguments;
+  private $profile, $webroot, $docroot, $arguments, $logging;
   private $sources= [];
 
   /**
@@ -26,8 +26,9 @@ class Environment {
    * @param  string|io.Path $docroot
    * @param  (string|util.PropertySource)[] $config
    * @param  string[] $arguments
+   * @param  string|string[]|web.Logging $logging Defaults to logging to console
    */
-  public function __construct($profile, $webroot, $docroot, $config, $arguments= []) {
+  public function __construct($profile, $webroot, $docroot, $config, $arguments= [], $logging= '-') {
     $this->profile= $profile;
     $this->webroot= $webroot instanceof Path ? $webroot : new Path($webroot);
     $this->docroot= $docroot instanceof Path ? $docroot : new Path($docroot);
@@ -40,6 +41,7 @@ public function __construct($profile, $webroot, $docroot, $config, $arguments= [
         $this->sources[]= new ResourcePropertySource($source);
       }
     }
+    $this->logging= $logging instanceof Logging ? $logging : Logging::of($logging);
     $this->arguments= $arguments;
   }
 
@@ -52,6 +54,9 @@ public function webroot() { return $this->webroot; }
   /** @return io.Path */
   public function docroot() { return $this->docroot; }
 
+  /** @return web.Logging */
+  public function logging() { return $this->logging; }
+
   /**
    * Gets properties
    *
diff --git a/src/main/php/web/Logging.class.php b/src/main/php/web/Logging.class.php
new file mode 100755
index 00000000..d26015a9
--- /dev/null
+++ b/src/main/php/web/Logging.class.php
@@ -0,0 +1,81 @@
+<?php namespace web;
+
+use web\logging\Sink;
+use web\logging\ToAllOf;
+
+class Logging {
+  private $sink;
+
+  /**
+   * Create an instance with a given sink
+   *
+   * @param  ?web.log.Sink $sink
+   */
+  public function __construct(Sink $sink= null) {
+    $this->sink= $sink;
+  }
+
+  /** @return ?web.log.Sink */
+  public function sink() { return $this->sink; }
+
+  /**
+   * Create an instance from a given command line argument
+   *
+   * @param  string $arg
+   * @return self
+   */
+  public static function of($arg) {
+    return new self(Sink::of($arg));
+  }
+
+  /**
+   * Pipe to a given sink
+   *
+   * @param  var $sink
+   * @return self
+   */
+  public function pipe($sink) {
+    if (null === $sink || $sink instanceof Sink) {
+      $this->sink= $sink;
+    } else {
+      $this->sink= Sink::of($sink);
+    }
+    return $this;
+  }
+
+  /**
+   * Tee to a given sink
+   *
+   * @param  var $sink
+   * @return self
+   */
+  public function tee($sink) {
+    if (null === $this->sink) {
+      $this->pipe($sink);
+    } else {
+      $this->sink= new ToAllOf($this->sink, $sink);
+    }
+    return $this;
+  }
+
+  /**
+   * Writes a log entry
+   *
+   * @param  web.Request $response
+   * @param  web.Response $response
+   * @param  ?web.Error $error Optional error
+   * @return void
+   */
+  public function log($request, $response, $error= null) {
+    $this->sink && $this->sink->log($request, $response, $error);
+  }
+
+  /**
+   * Returns logging target
+   *
+   * @return string
+   */
+  public function target() {
+    return $this->sink ? $this->sink->target() : '(no logging)';
+  }
+}
\ No newline at end of file
diff --git a/src/main/php/web/logging/Sink.class.php b/src/main/php/web/logging/Sink.class.php
new file mode 100755
index 00000000..847985c8
--- /dev/null
+++ b/src/main/php/web/logging/Sink.class.php
@@ -0,0 +1,50 @@
+<?php namespace web\logging;
+
+use util\log\LogCategory;
+
+/**
+ * Base class for all log sinks
+ *
+ * @test  xp://web.unittest.logging.SinkTest
+ */
+abstract class Sink {
+
+  /**
+   * Writes a log entry
+   *
+   * @param  web.Request $response
+   * @param  web.Response $response
+   * @param  ?web.Error $error Optional error
+   * @return void
+   */
+  public abstract function log($request, $response, $error);
+
+  /** @return string */
+  public function target() { return nameof($this); }
+
+  /**
+   * Factory method from various sources
+   *
+   * @param  var $arg
+   * @return ?self
+   */
+  public static function of($arg) {
+    if ('-' === $arg) {
+      return new ToConsole();
+    } else if (null === $arg) {
+      return null;
+    } else if (is_callable($arg)) {
+      return new ToFunction($arg);
+    } else if (is_array($arg)) {
+      switch (sizeof($arg)) {
+        case 0: return null;
+        case 1: return self::of($arg[0]);
+        default: return new ToAllOf(...$arg);
+      }
+    } else if ($arg instanceof LogCategory) {
+      return new ToCategory($arg);
+    } else {
+      return new ToFile($arg);
+    }
+  }
+}
\ No newline at end of file
diff --git a/src/main/php/web/logging/ToAllOf.class.php b/src/main/php/web/logging/ToAllOf.class.php
new file mode 100755
index 00000000..0f19b6ca
--- /dev/null
+++ b/src/main/php/web/logging/ToAllOf.class.php
@@ -0,0 +1,53 @@
+<?php namespace web\logging;
+
+/**
+ * Log sink which logs to all given sinks
+ *
+ * @test  xp://web.unittest.logging.ToAllOfTest
+ */
+class ToAllOf extends Sink {
+  private $sinks= [];
+
+  /**
+   * Creates a sink writing to all given other sinks
+   *
+   * @param  (web.log.Sink|util.log.LogCategory|function(web.Request, web.Response, string): void)... $arg
+   */
+  public function __construct(... $args) {
+    foreach ($args as $arg) {
+      if ($arg instanceof self) {
+        $this->sinks= array_merge($this->sinks, $arg->sinks);
+      } else if ($arg instanceof parent) {
+        $this->sinks[]= $arg;
+      } else {
+        $this->sinks[]= parent::of($arg);
+      }
+    }
+  }
+
+  /** @return web.log.Sink[] */
+  public function sinks() { return $this->sinks; }
+
+  /** @return string */
+  public function target() {
+    $s= '';
+    foreach ($this->sinks as $sink) {
+      $s.= ' & '.$sink->target();
+    }
+    return '('.substr($s, 3).')';
+  }
+
+  /**
+   * Writes a log entry
+   *
+   * @param  web.Request $response
+   * @param  web.Response $response
+   * @param  ?web.Error $error Optional error
+   * @return void
+   */
+  public function log($request, $response, $error) {
+    foreach ($this->sinks as $sink) {
+      $sink->log($request, $response, $error);
+    }
+  }
+}
\ No newline at end of file
diff --git a/src/main/php/web/logging/ToCategory.class.php b/src/main/php/web/logging/ToCategory.class.php
new file mode 100755
index 00000000..d29ff140
--- /dev/null
+++ b/src/main/php/web/logging/ToCategory.class.php
@@ -0,0 +1,32 @@
+<?php namespace web\logging;
+
+class ToCategory extends Sink {
+  private $cat;
+
+  /** @param util.log.LogCategory $cat */
+  public function __construct($cat) {
+    $this->cat= $cat;
+  }
+
+  /** @return string */
+  public function target() { return nameof($this).'('.$this->cat->toString().')'; }
+
+  /**
+   * Writes a log entry
+   *
+   * @param  web.Request $response
+   * @param  web.Response $response
+   * @param  ?web.Error $error Optional error
+   * @return void
+   */
+  public function log($request, $response, $error) {
+    $query= $request->uri()->query();
+    $uri= $request->uri()->path().($query ? '?'.$query : '');
+
+    if ($message) {
+      $this->cat->warn($response->status(), $request->method(), $uri, $error);
+    } else {
+      $this->cat->info($response->status(), $request->method(), $uri);
+    }
+  }
+}
\ No newline at end of file
diff --git a/src/main/php/web/logging/ToConsole.class.php b/src/main/php/web/logging/ToConsole.class.php
new file mode 100755
index 00000000..6f2ea205
--- /dev/null
+++ b/src/main/php/web/logging/ToConsole.class.php
@@ -0,0 +1,28 @@
+<?php namespace web\logging;
+
+use util\cmd\Console;
+
+class ToConsole extends Sink {
+
+  /**
+   * Writes a log entry
+   *
+   * @param  web.Request $response
+   * @param  web.Response $response
+   * @param  ?web.Error $error Optional error
+   * @return void
+   */
+  public function log($request, $response, $error) {
+    $query= $request->uri()->query();
+    Console::writeLinef(
+      "  \e[33m[%s %d %.3fkB]\e[0m %d %s %s %s",
+      date('Y-m-d H:i:s'),
+      getmypid(),
+      memory_get_usage() / 1024,
+      $response->status(),
+      $request->method(),
+      $request->uri()->path().($query ? '?'.$query : ''),
+      $message
+    );
+  }
+}
\ No newline at end of file
diff --git a/src/main/php/web/logging/ToFile.class.php b/src/main/php/web/logging/ToFile.class.php
new file mode 100755
index 00000000..51dff083
--- /dev/null
+++ b/src/main/php/web/logging/ToFile.class.php
@@ -0,0 +1,49 @@
+<?php namespace web\logging;
+
+use io\File;
+use lang\IllegalArgumentException;
+
+/**
+ * Logfile sink writing to a file
+ *
+ * @test  xp://web.unittest.logging.ToFileTest
+ */
+class ToFile extends Sink {
+  private $file;
+
+  /** @param string|io.File $file */
+  public function __construct($file) {
+    $this->file= $file instanceof File ? $file->getURI() : $file;
+    if (false === file_put_contents($this->file, '', FILE_APPEND | LOCK_EX)) {
+      $e= new IllegalArgumentException('Cannot write to '.$this->file);
+      \xp::gc(__FILE__);
+      throw $e;
+    }
+  }
+
+  /** @return string */
+  public function target() { return nameof($this).'('.$this->file.')'; }
+
+  /**
+   * Writes a log entry
+   *
+   * @param  web.Request $response
+   * @param  web.Response $response
+   * @param  ?web.Error $error Optional error
+   * @return void
+   */
+  public function log($request, $response, $error) {
+    $query= $request->uri()->query();
+    $line= sprintf(
+      "[%s %d %.3fkB] %d %s %s %s\n",
+      date('Y-m-d H:i:s'),
+      getmypid(),
+      memory_get_usage() / 1024,
+      $response->status(),
+      $request->method(),
+      $request->uri()->path().($query ? '?'.$query : ''),
+      $message
+    );
+    file_put_contents($this->file, $line, FILE_APPEND | LOCK_EX);
+  }
+}
\ No newline at end of file
diff --git a/src/main/php/web/logging/ToFunction.class.php b/src/main/php/web/logging/ToFunction.class.php
new file mode 100755
index 00000000..d92afd07
--- /dev/null
+++ b/src/main/php/web/logging/ToFunction.class.php
@@ -0,0 +1,22 @@
+<?php namespace web\logging;
+
+class ToFunction extends Sink {
+  private $function;
+
+  /** @param callable $function */
+  public function __construct($function) {
+    $this->function= cast($function, 'function(web.Request, web.Response, ?web.Error): void');
+  }
+
+  /**
+   * Writes a log entry
+   *
+   * @param  web.Request $response
+   * @param  web.Response $response
+   * @param  ?web.Error $error Optional error
+   * @return void
+   */
+  public function log($request, $response, $error) {
+    $this->function->__invoke($request, $response, $error);
+  }
+}
\ No newline at end of file
diff --git a/src/main/php/xp/web/Runner.class.php b/src/main/php/xp/web/Runner.class.php
index 8c359988..b7eaef27 100755
--- a/src/main/php/xp/web/Runner.class.php
+++ b/src/main/php/xp/web/Runner.class.php
@@ -31,6 +31,9 @@
  * The address the server listens to can be supplied via *-a {host}[:{port}]*.
  * The profile can be changed via *-p {profile}* (and can be anything!). One
  * or more configuration sources may be passed via *-c {file.ini|dir}*.
+ *
+ * The webserver log is sent to standard output by default. It can be redirected
+ * to a file via *-l /path/to/logfile.log*.
  */
 class Runner {
   private static $modes= [
@@ -86,6 +89,7 @@ public static function main($args) {
     $arguments= [];
     $config= [];
     $source= '.';
+    $log= [];
 
     for ($i= 0; $i < sizeof($args); $i++) {
        if ('-r' === $args[$i]) {
@@ -96,6 +100,8 @@ public static function main($args) {
         $profile= $args[++$i];
       } else if ('-c' === $args[$i]) {
         $config[]= $args[++$i];
+      } else if ('-l' === $args[$i]) {
+        $log[]= $args[++$i];
       } else if ('-m' === $args[$i]) {
         $arguments= explode(',', $args[++$i]);
         $mode= array_shift($arguments);
@@ -107,8 +113,15 @@ public static function main($args) {
       }
     }
 
-    $server= self::server($mode, $address, $arguments);
-    $server->serve($source, $profile, $webroot, $webroot->resolve($docroot), $config, array_slice($args, $i + 1));
+    self::server($mode, $address, $arguments)->serve(
+      $source,
+      $profile,
+      $webroot,
+      $webroot->resolve($docroot),
+      $config,
+      array_slice($args, $i + 1),
+      $log ?: '-'
+    );
     return 0;
   }
 }
\ No newline at end of file
diff --git a/src/main/php/xp/web/WebRunner.class.php b/src/main/php/xp/web/WebRunner.class.php
index 6a5b8934..b66c8586 100755
--- a/src/main/php/xp/web/WebRunner.class.php
+++ b/src/main/php/xp/web/WebRunner.class.php
@@ -13,38 +13,16 @@
  */
 class WebRunner {
 
-  /**
-   * Logs a request
-   *
-   * @param  web.Request $response
-   * @param  web.Response $response
-   * @param  string $message
-   * @return void
-   */
-  private static function log($request, $response, $message= null) {
-    $query= $request->uri()->query();
-    fprintf(STDOUT,
-      "  \e[33m[%s %d %.3fkB]\e[0m %d %s %s %s\n",
-      date('Y-m-d H:i:s'),
-      getmypid(),
-      memory_get_usage() / 1024,
-      $response->status(),
-      $request->method(),
-      $request->uri()->path().($query ? '?'.$query : ''),
-      $message
-    );
-  }
-
   /**
    * Sends an error
    *
    * @param  web.Request $response
    * @param  web.Response $response
-   * @param  web.Error $error
-   * @param  string $profile
+   * @param  web.Environment $env
+   * @param  ?web.Error $error
    * @return void
    */
-  private static function error($request, $response, $error, $profile) {
+  private static function error($request, $response, $env, $error) {
     if ($response->flushed()) {
       error_log($error->toString(), 4);  // 4 = SAPI error logger
     } else {
@@ -52,7 +30,7 @@ private static function error($request, $response, $error, $profile) {
       $message= Status::message($error->status());
 
       $response->answer($error->status(), $message);
-      foreach (['web/error-'.$profile.'.html', 'web/error.html'] as $variant) {
+      foreach (['web/error-'.$env->profile().'.html', 'web/error.html'] as $variant) {
         if (!$loader->providesResource($variant)) continue;
         $response->send(sprintf(
           $loader->getResource($variant),
@@ -64,12 +42,19 @@ private static function error($request, $response, $error, $profile) {
         break;
       }
     }
-    self::log($request, $response, $error->toString());
+    $env->logging()->log($request, $response, $error);
   }
 
   /** @param string[] $args */
   public static function main($args) {
-    $env= new Environment($args[2], $args[0], $args[1], explode('PATH_SEPARATOR', getenv('WEB_CONFIG')), explode('|', getenv('WEB_ARGS')));
+    $env= new Environment(
+      $args[2],
+      $args[0],
+      $args[1],
+      explode('PATH_SEPARATOR', getenv('WEB_CONFIG')),
+      explode('|', getenv('WEB_ARGS')),
+      getenv('WEB_LOG')
+    );
 
     $sapi= new SAPI();
     $request= new Request($sapi);
@@ -80,13 +65,13 @@ public static function main($args) {
     try {
       $application= (new Source(getenv('WEB_SOURCE'), $env))->application();
       $application->service($request, $response);
-      self::log($request, $response);
+      $env->logging()->log($request, $response);
     } catch (Error $e) {
-      self::error($request, $response, $e, $args[2]);
+      self::error($request, $response, $env, $e);
     } catch (\Throwable $e) {   // PHP7
-      self::error($request, $response, new InternalServerError($e), $args[2]);
+      self::error($request, $response, $env, new InternalServerError($e));
     } catch (\Exception $e) {   // PHP5
-      self::error($request, $response, new InternalServerError($e), $args[2]);
+      self::error($request, $response, $env, new InternalServerError($e));
     } finally {
       $response->flushed() || $response->flush();
     }
diff --git a/src/main/php/xp/web/srv/Develop.class.php b/src/main/php/xp/web/srv/Develop.class.php
index 14a10d92..78a6c2d1 100755
--- a/src/main/php/xp/web/srv/Develop.class.php
+++ b/src/main/php/xp/web/srv/Develop.class.php
@@ -9,6 +9,7 @@
 use lang\archive\ArchiveClassLoader;
 use peer\Socket;
 use util\cmd\Console;
+use web\Logging;
 
 class Develop implements Server {
   private $host, $port;
@@ -33,8 +34,9 @@ public function __construct($host, $port) {
    * @param  io.Path $docroot
    * @param  string[] $config
    * @param  string[] $args
+   * @param  string[] $logging
    */
-  public function serve($source, $profile, $webroot, $docroot, $config, $args) {
+  public function serve($source, $profile, $webroot, $docroot, $config, $args, $logging) {
 
     // PHP doesn't start with a nonexistant document root
     if (!$docroot->exists()) {
@@ -66,9 +68,10 @@ public function serve($source, $profile, $webroot, $docroot, $config, $args) {
     putenv('WEB_CONFIG='.implode('PATH_SEPARATOR', $config));
     putenv('WEB_ROOT='.$webroot);
     putenv('WEB_ARGS='.implode('|', $args));
+    putenv('WEB_LOG='.$logging);
 
     Console::writeLine("\e[33m@", nameof($this), "(HTTP @ `php ", implode(' ', $arguments), "`)\e[0m");
-    Console::writeLine("\e[1mServing ", $source, $config, "\e[0m");
+    Console::writeLine("\e[1mServing ", $source, $config, "\e[0m > ", Logging::of($logging)->target());
     Console::writeLine("\e[36m", str_repeat('═', 72), "\e[0m");
     Console::writeLine();
 
diff --git a/src/main/php/xp/web/srv/HttpProtocol.class.php b/src/main/php/xp/web/srv/HttpProtocol.class.php
index 63bfc1f0..c8285fc3 100755
--- a/src/main/php/xp/web/srv/HttpProtocol.class.php
+++ b/src/main/php/xp/web/srv/HttpProtocol.class.php
@@ -15,6 +15,7 @@
  * @test  xp://web.unittest.HttpProtocolTest
  */
 class HttpProtocol implements ServerProtocol {
+  private $application, $logging;
   public $server= null;
   private $close= false;
 
@@ -22,7 +23,7 @@ class HttpProtocol implements ServerProtocol {
    * Creates a new protocol instance
    *
    * @param  web.Application $application
-   * @param  function(web.Request, web.Response, ?lang.Throwable): void $logging
+   * @param  web.Logging $logging
    */
   public function __construct($application, $logging) {
     $this->application= $application;
@@ -57,7 +58,7 @@ private function sendError($request, $response, $error) {
         break;
       }
     }
-    $this->logging->__invoke($request, $response, $error->toString());
+    $this->logging->log($request, $response, $error);
   }
 
   /**
@@ -125,7 +126,7 @@ public function handleData($socket) {
 
     try {
       $this->application->service($request, $response);
-      $this->logging->__invoke($request, $response);
+      $this->logging->log($request, $response);
     } catch (Error $e) {
       $this->sendError($request, $response, $e);
     } catch (\Throwable $e) {   // PHP7
diff --git a/src/main/php/xp/web/srv/Server.class.php b/src/main/php/xp/web/srv/Server.class.php
index 22c4abb3..f5647f78 100755
--- a/src/main/php/xp/web/srv/Server.class.php
+++ b/src/main/php/xp/web/srv/Server.class.php
@@ -11,6 +11,7 @@ interface Server {
    * @param  io.Path $docroot
    * @param  string[] $config
    * @param  string[] $args
+   * @param  string[] $logging
    */
-  public function serve($source, $profile, $webroot, $docroot, $config, $args);
+  public function serve($source, $profile, $webroot, $docroot, $config, $args, $logging);
 }
\ No newline at end of file
diff --git a/src/main/php/xp/web/srv/Standalone.class.php b/src/main/php/xp/web/srv/Standalone.class.php
index 3aafe698..c884e711 100755
--- a/src/main/php/xp/web/srv/Standalone.class.php
+++ b/src/main/php/xp/web/srv/Standalone.class.php
@@ -22,27 +22,17 @@ public function __construct($server, $url) {
    * @param  io.Path $docroot
    * @param  string[] $config
    * @param  string[] $args
+   * @param  string[] $logging
    */
-  public function serve($source, $profile, $webroot, $docroot, $config, $args) {
-    $application= (new Source($source, new Environment($profile, $webroot, $docroot, $config, $args)))->application($args);
-
-    $this->server->setProtocol(new HttpProtocol($application, function($request, $response, $message= null) {
-      $query= $request->uri()->query();
-      Console::writeLinef(
-        "  \e[33m[%s %d %.3fkB]\e[0m %d %s %s %s",
-        date('Y-m-d H:i:s'),
-        getmypid(),
-        memory_get_usage() / 1024,
-        $response->status(),
-        $request->method(),
-        $request->uri()->path().($query ? '?'.$query : ''),
-        $message
-      );
-    }));
+  public function serve($source, $profile, $webroot, $docroot, $config, $args, $logging) {
+    $environment= new Environment($profile, $webroot, $docroot, $config, $args, $logging);
+    $application= (new Source($source, $environment))->application($args);
+
+    $this->server->setProtocol(new HttpProtocol($application, $environment->logging()));
     $this->server->init();
 
     Console::writeLine("\e[33m@", nameof($this), '(HTTP @ ', $this->server->socket->toString(), ")\e[0m");
-    Console::writeLine("\e[1mServing ", $application, $config, "\e[0m");
+    Console::writeLine("\e[1mServing ", $application, $config, "\e[0m > ", $environment->logging()->target());
     Console::writeLine("\e[36m", str_repeat('═', 72), "\e[0m");
     Console::writeLine();
 
diff --git a/src/test/php/web/unittest/HttpProtocolTest.class.php b/src/test/php/web/unittest/HttpProtocolTest.class.php
index 111cda01..cc416edc 100755
--- a/src/test/php/web/unittest/HttpProtocolTest.class.php
+++ b/src/test/php/web/unittest/HttpProtocolTest.class.php
@@ -1,16 +1,17 @@
 <?php namespace web\unittest;
 
-use xp\web\srv\HttpProtocol;
+use unittest\TestCase;
 use web\Application;
 use web\Environment;
-use unittest\TestCase;
+use web\Logging;
+use xp\web\srv\HttpProtocol;
 
 class HttpProtocolTest extends TestCase {
   private $log;
 
   /** @return void */
   public function setUp() {
-    $this->log= function($req, $res, $error= null) { };
+    $this->log= new Logging(null);
   }
 
   private function application($handler) {
diff --git a/src/test/php/web/unittest/LoggingTest.class.php b/src/test/php/web/unittest/LoggingTest.class.php
new file mode 100755
index 00000000..f5bf2b8c
--- /dev/null
+++ b/src/test/php/web/unittest/LoggingTest.class.php
@@ -0,0 +1,85 @@
+<?php namespace web\unittest;
+
+use web\Error;
+use web\Logging;
+use web\Request;
+use web\Response;
+use web\io\TestInput;
+use web\io\TestOutput;
+use web\logging\ToAllOf;
+use web\logging\ToFunction;
+
+class LoggingTest extends \unittest\TestCase {
+
+  #[@test]
+  public function can_create() {
+    new Logging(null);
+  }
+
+  #[@test]
+  public function can_create_with_sink() {
+    new Logging(new ToFunction(function($req, $res, $error) { }));
+  }
+
+  #[@test]
+  public function target() {
+    $sink= new ToFunction(function($req, $res, $error) { });
+    $this->assertEquals($sink->target(), (new Logging($sink))->target());
+  }
+
+  #[@test]
+  public function no_logging_target() {
+    $this->assertEquals('(no logging)', (new Logging(null))->target());
+  }
+
+  #[@test, @values([
+  #  ['GET /', null],
+  #  ['GET / Test', new Error(404, 'Test')],
+  #])]
+  public function log($expected, $error) {
+    $req= new Request(new TestInput('GET', '/'));
+    $res= new Response(new TestOutput());
+
+    $logged= [];
+    $log= new Logging(new ToFunction(function($req, $res, $error) use(&$logged) {
+      $logged[]= $req->method().' '.$req->uri()->path().($error ? ' '.$error->getMessage() : '');
+    }));
+    $log->log($req, $res, $error);
+
+    $this->assertEquals([$expected], $logged);
+  }
+
+  #[@test]
+  public function pipe() {
+    $a= new ToFunction(function($req, $res, $error) { /* a */ });
+    $b= new ToFunction(function($req, $res, $error) { /* b */ });
+    $this->assertEquals($b, (new Logging($a))->pipe($b)->sink());
+  }
+
+  #[@test]
+  public function tee() {
+    $a= new ToFunction(function($req, $res, $error) { /* a */ });
+    $b= new ToFunction(function($req, $res, $error) { /* b */ });
+    $this->assertEquals(new ToAllOf($a, $b), (new Logging($a))->tee($b)->sink());
+  }
+
+  #[@test]
+  public function tee_multiple() {
+    $a= new ToFunction(function($req, $res, $error) { /* a */ });
+    $b= new ToFunction(function($req, $res, $error) { /* b */ });
+    $c= new ToFunction(function($req, $res, $error) { /* c */ });
+    $this->assertEquals(new ToAllOf($a, $b, $c), (new Logging($a))->tee($b)->tee($c)->sink());
+  }
+
+  #[@test]
+  public function pipe_on_no_logging() {
+    $sink= new ToFunction(function($req, $res, $error) { });
+    $this->assertEquals($sink, (new Logging(null))->pipe($sink)->sink());
+  }
+
+  #[@test]
+  public function tee_on_no_logging() {
+    $sink= new ToFunction(function($req, $res, $error) { });
+    $this->assertEquals($sink, (new Logging(null))->tee($sink)->sink());
+  }
+}
\ No newline at end of file
diff --git a/src/test/php/web/unittest/logging/SinkTest.class.php b/src/test/php/web/unittest/logging/SinkTest.class.php
new file mode 100755
index 00000000..0cb59be3
--- /dev/null
+++ b/src/test/php/web/unittest/logging/SinkTest.class.php
@@ -0,0 +1,62 @@
+<?php namespace web\unittest\logging;
+
+use io\TempFile;
+use unittest\TestCase;
+use web\logging\Sink;
+use web\logging\ToAllOf;
+use web\logging\ToConsole;
+use web\logging\ToFile;
+use web\logging\ToFunction;
+
+class SinkTest extends TestCase {
+
+  #[@test, @values([[null], [[]]])]
+  public function no_logging($arg) {
+    $this->assertNull(Sink::of($arg));
+  }
+
+  #[@test]
+  public function logging_to_console() {
+    $this->assertInstanceOf(ToConsole::class, Sink::of('-'));
+  }
+
+  #[@test]
+  public function logging_to_function() {
+    $this->assertInstanceOf(ToFunction::class, Sink::of(function($req, $res, $error) { }));
+  }
+
+  #[@test]
+  public function logging_to_file() {
+    $t= new TempFile('log');
+    try {
+      $this->assertInstanceOf(ToFile::class, Sink::of($t));
+    } finally {
+      $t->unlink();
+    }
+  }
+
+  #[@test]
+  public function logging_to_file_by_name() {
+    $t= new TempFile('log');
+    try {
+      $this->assertInstanceOf(ToFile::class, Sink::of($t->getURI()));
+    } finally {
+      $t->unlink();
+    }
+  }
+
+  #[@test]
+  public function logging_to_all_of() {
+    $t= new TempFile('log');
+    try {
+      $this->assertInstanceOf(ToAllOf::class, Sink::of(['-', $t]));
+    } finally {
+      $t->unlink();
+    }
+  }
+
+  #[@test]
+  public function logging_to_all_of_flattened_when_only_one_argument_passed() {
+    $this->assertInstanceOf(ToConsole::class, Sink::of(['-']));
+  }
+}
\ No newline at end of file
diff --git a/src/test/php/web/unittest/logging/ToAllOfTest.class.php b/src/test/php/web/unittest/logging/ToAllOfTest.class.php
new file mode 100755
index 00000000..f876d0a5
--- /dev/null
+++ b/src/test/php/web/unittest/logging/ToAllOfTest.class.php
@@ -0,0 +1,77 @@
+<?php namespace web\unittest\logging;
+
+use unittest\TestCase;
+use web\Error;
+use web\Request;
+use web\Response;
+use web\io\TestInput;
+use web\io\TestOutput;
+use web\logging\ToAllOf;
+use web\logging\ToConsole;
+use web\logging\ToFunction;
+
+class ToAllOfTest extends TestCase {
+
+  #[@test]
+  public function can_create_without_args() {
+    new ToAllOf();
+  }
+
+  #[@test]
+  public function can_create_with_sink() {
+    new ToAllOf(new ToFunction(function($req, $res, $error) { }));
+  }
+
+  #[@test]
+  public function can_create_with_string() {
+    new ToAllOf('-');
+  }
+
+  #[@test]
+  public function sinks() {
+    $a= new ToConsole();
+    $b= new ToFunction(function($req, $res, $error) {  });
+    $this->assertEquals([$a, $b], (new ToAllOf($a, $b))->sinks());
+  }
+
+  #[@test]
+  public function sinks_are_merged_when_passed_ToAllOf_instance() {
+    $a= new ToConsole();
+    $b= new ToFunction(function($req, $res, $error) {  });
+    $this->assertEquals([$a, $b], (new ToAllOf(new ToAllOf($a, $b)))->sinks());
+  }
+
+  #[@test]
+  public function sinks_are_empty_when_created_without_arg() {
+    $this->assertEquals([], (new ToAllOf())->sinks());
+  }
+
+  #[@test]
+  public function targets() {
+    $a= new ToConsole();
+    $b= new ToFunction(function($req, $res, $error) { });
+    $this->assertEquals('(web.logging.ToConsole & web.logging.ToFunction)', (new ToAllOf($a, $b))->target());
+  }
+
+  #[@test, @values([
+  #  [['a' => ['GET /'], 'b' => ['GET /']], null],
+  #  [['a' => ['GET / Test'], 'b' => ['GET / Test']], new Error(404, 'Test')],
+  #])]
+  public function logs_to_all($expected, $error) {
+    $req= new Request(new TestInput('GET', '/'));
+    $res= new Response(new TestOutput());
+
+    $logged= ['a' => [], 'b' => []];
+    $sink= new ToAllOf(
+      new ToFunction(function($req, $res, $error) use(&$logged) {
+        $logged['a'][]= $req->method().' '.$req->uri()->path().($error ? ' '.$error->getMessage() : '');
+      }),
+      new ToFunction(function($req, $res, $error) use(&$logged) {
+        $logged['b'][]= $req->method().' '.$req->uri()->path().($error ? ' '.$error->getMessage() : '');
+      })
+    );
+    $sink->log($req, $res, $error);
+
+    $this->assertEquals($expected, $logged);
+  }
+}
\ No newline at end of file
diff --git a/src/test/php/web/unittest/logging/ToFileTest.class.php b/src/test/php/web/unittest/logging/ToFileTest.class.php
new file mode 100755
index 00000000..3947965f
--- /dev/null
+++ b/src/test/php/web/unittest/logging/ToFileTest.class.php
@@ -0,0 +1,40 @@
+<?php namespace web\unittest\logging;
+
+use io\TempFile;
+use lang\IllegalArgumentException;
+use unittest\TestCase;
+use web\logging\ToFile;
+
+class ToFileTest extends TestCase {
+  private $temp;
+
+  /** @return void */
+  public function setUp() {
+    $this->temp= new TempFile('sink');
+  }
+
+  /** @return void */
+  public function tearDown() {
+    if ($this->temp->exists()) {
+      $this->temp->setPermissions(0600);
+      $this->temp->unlink();
+    }
+  }
+
+  #[@test]
+  public function can_create() {
+    new ToFile($this->temp);
+  }
+
+  #[@test]
+  public function file_created_during_constructor_call() {
+    new ToFile($this->temp);
+    $this->assertTrue($this->temp->exists());
+  }
+
+  #[@test, @expect(IllegalArgumentException::class)]
+  public function raises_error_if_file_cannot_be_written_to() {
+    $this->temp->setPermissions(0000);
+    new ToFile($this->temp);
+  }
+}
\ No newline at end of file