diff -r a4a06840209a -r a07253cf2ca4 launcher/src/main/java/org/apidesign/bck2brwsr/launcher/Launcher.java
--- a/launcher/src/main/java/org/apidesign/bck2brwsr/launcher/Launcher.java	Wed Jan 30 18:27:57 2013 +0100
+++ b/launcher/src/main/java/org/apidesign/bck2brwsr/launcher/Launcher.java	Thu Jan 31 16:58:27 2013 +0100
@@ -24,7 +24,8 @@
 import org.apidesign.vm4brwsr.Bck2Brwsr;
 
 /** An abstraction for executing tests in a Bck2Brwsr virtual machine.
- * Either in JavaScript engine, or in external browser.
+ * Either in {@linkm Launcher#createJavaScript JavaScript engine}, 
+ * or in {@linkm Launcher#createBrowser external browser}.
  *
  * @author Jaroslav Tulach <jtulach@netbeans.org>
  */
@@ -32,39 +33,83 @@
 
     Launcher() {
     }
+
+    /** Initializes the launcher. This may mean starting a web browser or
+     * initializing execution engine.
+     * @throws IOException if something goes wrong
+     */
+    public abstract void initialize() throws IOException;
     
-    abstract MethodInvocation addMethod(Class<?> clazz, String method, String html) throws IOException; 
-
-    public abstract void initialize() throws IOException;
+    /** Shuts down the launcher.
+     * @throws IOException if something goes wrong
+     */
     public abstract void shutdown() throws IOException;
-    public MethodInvocation invokeMethod(Class<?> clazz, String method, String html) throws IOException {
-        return addMethod(clazz, method, html);
+    
+    
+    /** Builds an invocation context. The context can later be customized
+     * and {@link InvocationContext#invoke() invoked}.
+     * 
+     * @param clazz the class to execute method from
+     * @param method the method to execute
+     * @return the context pointing to the selected method
+     */
+    public InvocationContext createInvocation(Class<?> clazz, String method) {
+        return new InvocationContext(this, clazz, method);
     }
     
-    
 
+    /** Creates launcher that uses internal JavaScript engine (Rhino).
+     * @return the launcher
+     */
     public static Launcher createJavaScript() {
         final JSLauncher l = new JSLauncher();
         l.addClassLoader(Bck2Brwsr.class.getClassLoader());
         return l;
     }
     
+    /** Creates launcher that is using external browser.
+     * 
+     * @param cmd <code>null</code> to use <code>java.awt.Desktop</code> to show the launcher
+     *    or a string to execute in an external process (with a parameter to the URL)
+     * @return launcher executing in external browser.
+     */
     public static Launcher createBrowser(String cmd) {
         final Bck2BrwsrLauncher l = new Bck2BrwsrLauncher(cmd);
         l.addClassLoader(Bck2Brwsr.class.getClassLoader());
         l.setTimeout(180000);
         return l;
     }
+    
+    /** Starts an HTTP server which provides access to classes and resources
+     * available in the <code>classes</code> URL and shows a start page
+     * available as {@link ClassLoader#getResource(java.lang.String)} from the
+     * provide classloader. Opens a browser with URL showing the start page.
+     * 
+     * @param classes classloader offering access to classes and resources
+     * @param startpage page to show in the browser
+     * @return interface that allows one to stop the server
+     * @throws IOException if something goes wrong
+     */
     public static Closeable showURL(URLClassLoader classes, String startpage) throws IOException {
         Bck2BrwsrLauncher l = new Bck2BrwsrLauncher(null);
         l.addClassLoader(classes);
         l.showURL(startpage);
         return l;
     }
+    /** Starts an HTTP server which provides access to certain directory.
+     * The <code>startpage</code> should be relative location inside the root 
+     * driecotry
+     * Opens a browser with URL showing the start page.
+     * 
+     * @param directory the root directory on disk
+     * @praam startpage relative path from the root to the page
+     * @exception IOException if something goes wrong.
+     */
     public static Closeable showDir(File directory, String startpage) throws IOException {
         Bck2BrwsrLauncher l = new Bck2BrwsrLauncher(null);
         l.showDirectory(directory, startpage);
         return l;
     }
 
+    abstract InvocationContext runMethod(InvocationContext c) throws IOException; 
 }