I'm not sure about GAE, but as to Quercus in general: You get to write in Not Java while your employer gets to deploy on the JVM.
This is huge.
Take Jython for example: Put jython.jar in WEB-INF/lib/, add a small stanza to WEB-INF/web.xml, write a WSGI-compliant app in Python. When you're done, you can zip it up and deploy it on Tomcat. None of the existing infrastructure needs to change, and you get to write in a more expressive language. That's how we'll sneak better things into enterprise.
This is huge.
Take Jython for example: Put jython.jar in WEB-INF/lib/, add a small stanza to WEB-INF/web.xml, write a WSGI-compliant app in Python. When you're done, you can zip it up and deploy it on Tomcat. None of the existing infrastructure needs to change, and you get to write in a more expressive language. That's how we'll sneak better things into enterprise.