diff --git a/dev/DevelopmentAdmin.php b/dev/DevelopmentAdmin.php
index 982d9dce9..83f5a2daf 100644
--- a/dev/DevelopmentAdmin.php
+++ b/dev/DevelopmentAdmin.php
@@ -20,12 +20,17 @@ class DevelopmentAdmin extends Controller {
 		$actions = array(
 			"build" => "Build/rebuild this environment (formerly db/build).  Call this whenever you have updated your project sources",
 			"tests" => "See a list of unit tests to run",
+			"tests/all" => "Run all tests",
+			"modules/add" => "Add a module, for example, 'sake dev/modules/add ecommerce'",
 			"tasks" => "See a list of build tasks to run",
 			"viewcode" => "Read source code in a literate programming style",
 		);
 		
 		// Web mode
 		if(!Director::is_cli()) {
+			// This action is sake-only right now.
+			unset($actions["modules/add"]);
+			
 			$renderer = new DebugView();
 			$renderer->writeHeader();
 			$renderer->writeInfo("Sapphire Development Tools", Director::absoluteBaseURL());
@@ -57,6 +62,10 @@ class DevelopmentAdmin extends Controller {
 		return new TaskRunner();
 	}
 	
+	function modules() {
+		return new ModuleManager();
+	}
+	
 	function build() {
 		$renderer = new DebugView();
 		$renderer->writeHeader();
diff --git a/dev/ModuleManager.php b/dev/ModuleManager.php
new file mode 100644
index 000000000..f65199f06
--- /dev/null
+++ b/dev/ModuleManager.php
@@ -0,0 +1,99 @@
+<?php
+
+/**
+ * This is part of the developer tools, and is responsible for installing and uninstalling modules
+ *
+ * Please note that this is experimental and the interface may change in the future.
+ * Also, it requires that your site is checked into SVN, and that SVN is installed.
+ *
+ * For best results, use the "sake" command line tool:
+ *
+ * cd /my/project/
+ * sake dev/modules/add ecommerce
+ */
+class ModuleManager extends RequestHandlingData {
+	protected $moduleBase = "http://svn.silverstripe.com/open/modules/";
+	
+	static $allowed_actions = array(
+		'add',
+	);
+	
+	/**
+	 * Add a module to this project.
+	 * This is designed to be called from sake.
+	 * 
+	 * Usage: sake dev/modules/add ecommerce forum/tags/0.1
+	 */
+	function add() {
+		if(isset($_GET['args'])) {
+			$modules = $_GET['args'];
+			foreach($modules as $module) {
+				if(preg_match('/^[a-zA-Z0-9\/_-]+$/', $module)) {
+					// Default to trunk version of a module
+					if(strpos($module,'/') === false) $module = "$module/trunk";
+
+					$svnURL = $this->moduleBase . $module;
+					
+					if($this->svnUrlExists($svnURL)) {
+						$moduleDir = strtok($module,'/');
+						echo "Linking directory '$moduleDir' to '$svnURL' using svn:externals...";
+						$this->svnAddExternal(Director::baseFolder(), $moduleDir, $svnURL);
+
+						echo "Calling SVN update to get the new code...";
+						$this->svnUpdate(Director::baseFolder());
+						
+						echo "Rebuilding...";
+						
+						// todo: we should be able to call the 'model' of the builder rather than its 'controller'
+						// it would make it easier to tailor the output
+						$da = new DevelopmentAdmin();
+						$da->build();
+						
+					} else {
+						echo "Can't find '$svnURL' in SVN";
+					}
+					
+				} else {
+					echo "Bad module '$module'";
+				}
+				
+			}
+			
+		}
+	}
+
+
+	/**
+	 * Calls svn update
+	 */
+	protected function svnUpdate($baseDir) {
+		$CLI_baseDir = escapeshellarg($baseDir);
+		`svn update $CLI_baseDir`;
+	}
+	
+	/**
+	 * Returns true if the given SVN url exists
+	 */
+	protected function svnUrlExists($svnURL) {
+		$CLI_svnURL = escapeshellarg($svnURL);
+		$info = `svn info --xml $CLI_svnURL`;
+		$xmlInfo = new SimpleXmlElement($info);
+		
+		return $xmlInfo->entry ? true : false;
+	}
+
+	/**
+	 * Add a new entry to the svn externals
+	 */
+	protected function svnAddExternal($baseDir, $externalDir, $externalURL) {
+		$CLI_baseDir = escapeshellarg($baseDir);
+		$oldExternals = trim(`svn propget svn:externals $CLI_baseDir`);
+		$newExternals = "$oldExternals\n$externalDir/	$externalURL";
+		
+		$CLI_newExternals = escapeshellarg($newExternals);
+		`svn propset svn:externals $CLI_newExternals $CLI_baseDir`;
+	}
+	
+}
+
+?>
\ No newline at end of file