diff --git a/bin/composer b/bin/composer
index b188aa337..15b9a907c 100755
--- a/bin/composer
+++ b/bin/composer
@@ -29,6 +29,7 @@ $rm->setRepositoryClass('package', 'Composer\Repository\PackageRepository');
 // initialize download manager
 $dm = new Downloader\DownloadManager();
 $dm->setDownloader('git',  new Downloader\GitDownloader());
+$dm->setDownloader('hg', new Downloader\HgDownloader());
 $dm->setDownloader('pear', new Downloader\PearDownloader());
 $dm->setDownloader('zip',  new Downloader\ZipDownloader());
 
diff --git a/src/Composer/Downloader/HgDownloader.php b/src/Composer/Downloader/HgDownloader.php
new file mode 100644
index 000000000..32d23b770
--- /dev/null
+++ b/src/Composer/Downloader/HgDownloader.php
@@ -0,0 +1,74 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Downloader;
+
+use Composer\Package\PackageInterface;
+
+/**
+ * @author Per Bernhardt <plb@webfactory.de>
+ */
+class HgDownloader implements DownloaderInterface
+{
+    /**
+     * {@inheritDoc}
+     */
+    public function getInstallationSource()
+    {
+        return 'source';
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function download(PackageInterface $package, $path)
+    {
+        if (!$package->getSourceReference()) {
+            throw new \InvalidArgumentException('The given package is missing reference information');
+        }
+
+        $url = escapeshellarg($package->getSourceUrl());
+        $ref = escapeshellarg($package->getSourceReference());
+        system(sprintf('hg clone %s %s && cd %2$s && hg up %s', $url, $path, $ref));
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function update(PackageInterface $initial, PackageInterface $target, $path)
+    {
+        if (!$target->getSourceReference()) {
+            throw new \InvalidArgumentException('The given package is missing reference information');
+        }
+
+        $this->enforceCleanDirectory($path);
+        system(sprintf('cd %s && hg pull && hg up %s', $path, escapeshellarg($target->getSourceReference())));
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function remove(PackageInterface $package, $path)
+    {
+        $this->enforceCleanDirectory($path);
+        $fs = new Util\Filesystem();
+        $fs->remove($path);
+    }
+
+    private function enforceCleanDirectory($path)
+    {
+        exec(sprintf('cd %s && hg st', $path), $output);
+        if (implode('', $output)) {
+            throw new \RuntimeException('Source directory has uncommitted changes');
+        }
+    }
+}
diff --git a/src/Composer/Repository/Vcs/GitBitbucketDriver.php b/src/Composer/Repository/Vcs/GitBitbucketDriver.php
new file mode 100644
index 000000000..1ac4f85f3
--- /dev/null
+++ b/src/Composer/Repository/Vcs/GitBitbucketDriver.php
@@ -0,0 +1,163 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Repository\Vcs;
+
+use Composer\Json\JsonFile;
+
+/**
+ * @author Per Bernhardt <plb@webfactory.de>
+ */
+class GitBitbucketDriver implements VcsDriverInterface
+{
+    protected $url;
+    protected $owner;
+    protected $repository;
+    protected $tags;
+    protected $branches;
+    protected $rootIdentifier;
+    protected $infoCache = array();
+
+    public function __construct($url)
+    {
+        $this->url = $url;
+        preg_match('#^https://bitbucket\.org/([^/]+)/(.+?)\.git$#', $url, $match);
+        $this->owner = $match[1];
+        $this->repository = $match[2];
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function initialize()
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getRootIdentifier()
+    {
+        if (null === $this->rootIdentifier) {
+            $repoData = json_decode(file_get_contents('https://api.bitbucket.org/1.0/repositories/'.$this->owner.'/'.$this->repository), true);
+            $this->rootIdentifier = $repoData['main_branch'] ?: 'master';
+        }
+
+        return $this->rootIdentifier;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getUrl()
+    {
+        return $this->url;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getSource($identifier)
+    {
+        $label = array_search($identifier, $this->getTags()) ?: $identifier;
+
+        return array('type' => 'git', 'url' => $this->getUrl(), 'reference' => $label);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getDist($identifier)
+    {
+        $label = array_search($identifier, $this->getTags()) ?: $identifier;
+        $url = 'https://bitbucket.org/'.$this->owner.'/'.$this->repository.'/get/'.$label.'.zip';
+
+        return array('type' => 'zip', 'url' => $url, 'reference' => $label, 'shasum' => '');
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getComposerInformation($identifier)
+    {
+        if (!isset($this->infoCache[$identifier])) {
+            $composer = @file_get_contents('https://bitbucket.org/'.$this->owner.'/'.$this->repository.'/raw/'.$identifier.'/composer.json');
+            if (!$composer) {
+                throw new \UnexpectedValueException('Failed to retrieve composer information for identifier '.$identifier.' in '.$this->getUrl());
+            }
+
+            $composer = JsonFile::parseJson($composer);
+
+            if (!isset($composer['time'])) {
+                $changeset = json_decode(file_get_contents('https://api.bitbucket.org/1.0/repositories/'.$this->owner.'/'.$this->repository.'/changesets/'.$identifier), true);
+                $composer['time'] = $changeset['timestamp'];
+            }
+            $this->infoCache[$identifier] = $composer;
+        }
+
+        return $this->infoCache[$identifier];
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getTags()
+    {
+        if (null === $this->tags) {
+            $tagsData = json_decode(file_get_contents('https://api.bitbucket.org/1.0/repositories/'.$this->owner.'/'.$this->repository.'/tags'), true);
+            $this->tags = array();
+            foreach ($tagsData as $tag => $data) {
+                $this->tags[$tag] = $data['raw_node'];
+            }
+        }
+
+        return $this->tags;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getBranches()
+    {
+        if (null === $this->branches) {
+            $branchData = json_decode(file_get_contents('https://api.bitbucket.org/1.0/repositories/'.$this->owner.'/'.$this->repository.'/branches'), true);
+            $this->branches = array();
+            foreach ($branchData as $branch => $data) {
+                $this->branches[$branch] = $data['raw_node'];
+            }
+        }
+
+        return $this->branches;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function hasComposerFile($identifier)
+    {
+        try {
+            $this->getComposerInformation($identifier);
+            return true;
+        } catch (\Exception $e) {
+        }
+
+        return false;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public static function supports($url, $deep = false)
+    {
+        return preg_match('#^https://bitbucket\.org/([^/]+)/(.+?)\.git$#', $url, $match);
+    }
+}
diff --git a/src/Composer/Repository/Vcs/GitDriver.php b/src/Composer/Repository/Vcs/GitDriver.php
index b74f2e87e..3661fe046 100644
--- a/src/Composer/Repository/Vcs/GitDriver.php
+++ b/src/Composer/Repository/Vcs/GitDriver.php
@@ -46,7 +46,7 @@ class GitDriver implements VcsDriverInterface
         if (null === $this->rootIdentifier) {
             $this->rootIdentifier = 'master';
             exec(sprintf('cd %s && git branch --no-color -r', escapeshellarg($this->tmpDir)), $output);
-            foreach ($output as $key => $branch) {
+            foreach ($output as $branch) {
                 if ($branch && preg_match('{/HEAD +-> +[^/]+/(\S+)}', $branch, $match)) {
                     $this->rootIdentifier = $match[1];
                     break;
@@ -132,7 +132,7 @@ class GitDriver implements VcsDriverInterface
             $branches = array();
 
             exec(sprintf('cd %s && git branch --no-color -rv', escapeshellarg($this->tmpDir)), $output);
-            foreach ($output as $key => $branch) {
+            foreach ($output as $branch) {
                 if ($branch && !preg_match('{^ *[^/]+/HEAD }', $branch)) {
                     preg_match('{^ *[^/]+/(\S+) *([a-f0-9]+) .*$}', $branch, $match);
                     $branches[$match[1]] = $match[2];
diff --git a/src/Composer/Repository/Vcs/HgBitbucketDriver.php b/src/Composer/Repository/Vcs/HgBitbucketDriver.php
new file mode 100644
index 000000000..9c1c82b3b
--- /dev/null
+++ b/src/Composer/Repository/Vcs/HgBitbucketDriver.php
@@ -0,0 +1,164 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Repository\Vcs;
+
+use Composer\Json\JsonFile;
+
+/**
+ * @author Per Bernhardt <plb@webfactory.de>
+ */
+class HgBitbucketDriver implements VcsDriverInterface
+{
+    protected $url;
+    protected $owner;
+    protected $repository;
+    protected $tags;
+    protected $branches;
+    protected $rootIdentifier;
+    protected $infoCache = array();
+
+    public function __construct($url)
+    {
+        $this->url = $url;
+        preg_match('#^https://bitbucket\.org/([^/]+)/([^/]+)/?$#', $url, $match);
+        $this->owner = $match[1];
+        $this->repository = $match[2];
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function initialize()
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getRootIdentifier()
+    {
+        if (null === $this->rootIdentifier) {
+            $repoData = json_decode(file_get_contents('https://api.bitbucket.org/1.0/repositories/'.$this->owner.'/'.$this->repository.'/tags'), true);
+            $this->rootIdentifier = $repoData['tip']['raw_node'];
+        }
+
+        return $this->rootIdentifier;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getUrl()
+    {
+        return $this->url;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getSource($identifier)
+    {
+        $label = array_search($identifier, $this->getTags()) ?: $identifier;
+
+        return array('type' => 'hg', 'url' => $this->getUrl(), 'reference' => $label);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getDist($identifier)
+    {
+        $label = array_search($identifier, $this->getTags()) ?: $identifier;
+        $url = 'https://bitbucket.org/'.$this->owner.'/'.$this->repository.'/get/'.$label.'.zip';
+
+        return array('type' => 'zip', 'url' => $url, 'reference' => $label, 'shasum' => '');
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getComposerInformation($identifier)
+    {
+        if (!isset($this->infoCache[$identifier])) {
+            $composer = @file_get_contents('https://bitbucket.org/'.$this->owner.'/'.$this->repository.'/raw/'.$identifier.'/composer.json');
+            if (!$composer) {
+                throw new \UnexpectedValueException('Failed to retrieve composer information for identifier '.$identifier.' in '.$this->getUrl());
+            }
+
+            $composer = JsonFile::parseJson($composer);
+
+            if (!isset($composer['time'])) {
+                $changeset = json_decode(file_get_contents('https://api.bitbucket.org/1.0/repositories/'.$this->owner.'/'.$this->repository.'/changesets/'.$identifier), true);
+                $composer['time'] = $changeset['timestamp'];
+            }
+            $this->infoCache[$identifier] = $composer;
+        }
+
+        return $this->infoCache[$identifier];
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getTags()
+    {
+        if (null === $this->tags) {
+            $tagsData = json_decode(file_get_contents('https://api.bitbucket.org/1.0/repositories/'.$this->owner.'/'.$this->repository.'/tags'), true);
+            $this->tags = array();
+            foreach ($tagsData as $tag => $data) {
+                $this->tags[$tag] = $data['raw_node'];
+            }
+            unset($this->tags['tip']);
+        }
+
+        return $this->tags;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getBranches()
+    {
+        if (null === $this->branches) {
+            $branchData = json_decode(file_get_contents('https://api.bitbucket.org/1.0/repositories/'.$this->owner.'/'.$this->repository.'/branches'), true);
+            $this->branches = array();
+            foreach ($branchData as $branch => $data) {
+                $this->branches[$branch] = $data['raw_node'];
+            }
+        }
+
+        return $this->branches;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function hasComposerFile($identifier)
+    {
+        try {
+            $this->getComposerInformation($identifier);
+            return true;
+        } catch (\Exception $e) {
+        }
+
+        return false;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public static function supports($url, $deep = false)
+    {
+        return preg_match('#^https://bitbucket\.org/([^/]+)/([^/]+)/?$#', $url, $match);
+    }
+}
diff --git a/src/Composer/Repository/Vcs/HgDriver.php b/src/Composer/Repository/Vcs/HgDriver.php
new file mode 100644
index 000000000..29af3199b
--- /dev/null
+++ b/src/Composer/Repository/Vcs/HgDriver.php
@@ -0,0 +1,187 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Repository\Vcs;
+
+use Composer\Json\JsonFile;
+
+/**
+ * @author Per Bernhardt <plb@webfactory.de>
+ */
+class HgDriver implements VcsDriverInterface
+{
+    protected $url;
+    protected $tags;
+    protected $branches;
+    protected $rootIdentifier;
+    protected $infoCache = array();
+
+    public function __construct($url)
+    {
+        $this->url = $url;
+        $this->tmpDir = sys_get_temp_dir() . '/composer-' . preg_replace('{[^a-z0-9]}i', '-', $url) . '/';
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function initialize()
+    {
+        $url = escapeshellarg($this->url);
+        $tmpDir = escapeshellarg($this->tmpDir);
+        if (is_dir($this->tmpDir)) {
+            exec(sprintf('cd %s && hg pull -u', $tmpDir), $output);
+        } else {
+            exec(sprintf('hg clone %s %s', $url, $tmpDir), $output);
+        }
+
+        $this->getTags();
+        $this->getBranches();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getRootIdentifier()
+    {
+        $tmpDir = escapeshellarg($this->tmpDir);
+        if (null === $this->rootIdentifier) {
+            exec(sprintf('cd %s && hg tip --template "{rev}:{node|short}" --color never', $tmpDir), $output);
+            $this->rootIdentifier = $output[0];
+        }
+        
+        return $this->rootIdentifier;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getUrl()
+    {
+        return $this->url;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getSource($identifier)
+    {
+        $label = array_search($identifier, (array)$this->tags) ? : $identifier;
+
+        return array('type' => 'hg', 'url' => $this->getUrl(), 'reference' => $label);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getDist($identifier)
+    {
+        return null;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getComposerInformation($identifier)
+    {
+        if (!isset($this->infoCache[$identifier])) {
+            exec(sprintf('cd %s && hg cat --color never -r %s composer.json', escapeshellarg($this->tmpDir), escapeshellarg($identifier)), $output);
+            $composer = implode("\n", $output);
+            unset($output);
+
+            if (!$composer) {
+                throw new \UnexpectedValueException('Failed to retrieve composer information for identifier ' . $identifier . ' in ' . $this->getUrl());
+            }
+
+            $composer = JsonFile::parseJson($composer);
+
+            if (!isset($composer['time'])) {
+                exec(sprintf('cd %s && hg log --template "{date|rfc822date}" -r %s', escapeshellarg($this->tmpDir), escapeshellarg($identifier)), $output);
+                $date = new \DateTime($output[0]);
+                $composer['time'] = $date->format('Y-m-d H:i:s');
+            }
+            $this->infoCache[$identifier] = $composer;
+        }
+
+        return $this->infoCache[$identifier];
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getTags()
+    {
+        if (null === $this->tags) {
+            exec(sprintf('cd %s && hg tags --color never', escapeshellarg($this->tmpDir)), $output);
+            foreach ($output as $tag) {
+                preg_match('(^([^\s]+)[\s]+[\d+]:(.*)$)', $tag, $match);
+                $tags[$match[1]] = $match[2];
+            }
+            unset($tags['tip']);
+            $this->tags = $tags;
+        }
+
+        return $this->tags;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getBranches()
+    {
+        if (null === $this->branches) {
+            $branches = array();
+
+            exec(sprintf('cd %s && hg branches --color never', escapeshellarg($this->tmpDir)), $output);
+            foreach ($output as $branch) {
+                preg_match('(^([^\s]+)[\s]+[\d+]:(.*)$)', $branch, $match);
+                $branches[$match[1]] = $match[2];
+            }
+
+            $this->branches = $branches;
+        }
+
+        return $this->branches;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function hasComposerFile($identifier)
+    {
+        try {
+            $this->getComposerInformation($identifier);
+            return true;
+        } catch (\Exception $e) {
+        }
+
+        return false;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public static function supports($url, $deep = false)
+    {
+        if (preg_match('#(^(?:https?|ssh)://(?:[^@]@)?bitbucket.org|https://(?:.*?)\.kilnhg.com)#i', $url)) {
+            return true;
+        }
+
+        if (!$deep) {
+            return false;
+        }
+
+        exec(sprintf('hg identify %s', escapeshellarg($url)), $output);
+
+        return (boolean)$output;
+    }
+}
diff --git a/src/Composer/Repository/VcsRepository.php b/src/Composer/Repository/VcsRepository.php
index 5b5c4a8d4..5e13ac151 100644
--- a/src/Composer/Repository/VcsRepository.php
+++ b/src/Composer/Repository/VcsRepository.php
@@ -31,8 +31,10 @@ class VcsRepository extends ArrayRepository
 
         $drivers = array(
             'Composer\Repository\Vcs\GitHubDriver',
+            'Composer\Repository\Vcs\GitBitbucketDriver',
             'Composer\Repository\Vcs\GitDriver',
-            'Composer\Repository\Vcs\SvnDriver',
+            'Composer\Repository\Vcs\HgBitbucketDriver',
+            'Composer\Repository\Vcs\HgDriver',
         );
 
         foreach ($drivers as $driver) {