Google and MIT are pleased to announce the initial free and open-source release from Google of the App Inventor source code

Download
http://code.google.com/p/app-inventor-releases/downloads/list

Wiki Linux Mac
http://code.google.com/p/app-inventor-releases/wiki/BuildingAndRunning
1. Clone the Source! 2. Install dev-java/ant 3. Goto Appinventor-Dir bash: ant 4. bash: ant tests 5. Start the AppEngine Java Service (Download here: http://code.google.com/intl/de-DE/appengine/downloads.html#Download_the_Google_App_Engine_SDK) 6. bash: RunLocalBuildServer!

Wiki Windows
http://sites.jsoft.com/appinventor/home/gsuac/server/settingup/gsuar#TOC-your-war-folder