.

See also the official App Engine for supported librarieshttp://groups.google.com/group/google-appengine-java/web/will-it-play-in-app-engine

.

.

Web frameworks:

.

Restlethttp://blog.noelios.com/2009/04/11/restlet-in-the-cloud-with-google-app-engine/

.

Vaadinhttp://vaadin.com/

.

Sweet (Scala)http://gaesweet.appspot.com

.

Struts 2http://gaestruts2.appspot.com

.

Spring MVC(Unless you are using @Resource, which is not supported)

.

Sinatrahttp://blog.bigcurl.de/2009/04/running-sinatra-apps-on-google.html

.

Wickethttp://www.danwalmsley.com/2009/04/08/apache-wicket-on-google-app-engine-for-java/

.

http://stronglytypedblog.blogspot.com/2009/04/wicket-on-google-app-engine.html

.

.

Lifthttp://lift-example.appspot.com/

.

JRuby On Railshttp://olabini.com/blog/2009/04/jruby-on-rails-on-google-app-engine/

.

JSF 1.1 (not 1.2)http://myfaces.apache.org/download.html

.

Gwthttp://code.google.com/intl/fr-FR/webtoolkit/

.

Tapestry 5.0.18http://ganshane.appspot.com/

.

Click Frameworkhttp://incubator.apache.org/click/

.

Grailshttp://petclinic-grails.appspot.com/

.

Slim3http://higayasuo.appspot.com/

.

Play! Frameworkhttp://www.playframework.org/

.

TemplateEngine

.

LiteXMLhttp://code.google.com/p/lite/wiki/Lite4JavaServlet

.

.

Script langages:

.

Scalahttp://lift-example.appspot.com/

.

Rhinohttp://dev.helma.org/ng/Running+Rhino+and+Helma+NG+on+Google+App+Engine/

.

PHPhttp://quercus.caucho.com/

.

JRubyhttp://olabini.com/blog/2009/04/jruby-on-rails-on-google-app-engine/

.

Groovyhttp://blog.springsource.com/2009/04/07/write-your-google-app-engine-applications-in-groovy/ [1]

.

Jythonhttp://groups.google.com/group/google-appengine-java/web/jython-r5996-patched-for-appengine.jar

.

Jython - working - latesthttp://opensource.xhaus.com/projects/modjy/wiki/ModjyGoogleAppEngine

.

BeanShell

.

Other frameworks:

.

Helma NGhttp://dev.helma.org/ng/Running+Rhino+and+Helma+NG+on+Google+App+Engine/

.

H2 Databasehttp://www.h2database.com/html/changelog.html

.

Guicehttp://groups.google.com/group/google-guice/browse_thread/thread/13a63dc40684abe8?pli=1

.

Compasshttp://www.kimchy.org/searchable-google-appengine-with-compass/

.

XStreamhttp://paulhammant.com/blog/google-app-engine-for-java-with-rich-ruby-clients.html

.

PicoContainer Web Remotinghttp://paulhammant.com/blog/google-app-engine-for-java-with-rich-ruby-clients.html

.

PicoContainerhttp://paulhammant.com/blog/google-app-engine-for-java-with-rich-ruby-clients.html

.

DataNucleus RESThttp://www.datanucleus.org/products/accessplatform_1_1/rest/api.html

.

DWRhttp://youactivist.appspot.com/dwr/test/Demo

.

Twitter4Jhttp://yusuke.homeip.net/twitter4j/
[1] From the blog entry: "...but for instance, Grails applications aren't working on the current version of Google App Engine. We'll continue working on this with the Google App Engine team, so that you may use Grails as well, for more demanding applications." --Klauer Monday, April 13, 2009 10:12:18 AM