It offers users the ability to build and host web applications on Google's infrastructure. Costs nothing unless you get a lot of traffic and/or use a lot of resources (database or CPU). Applications can be written in PythonLanguage or JavaLanguage.
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How come there are not any on-line examples?

''Is http://www.youtube.com/watch?v=bfgO-LXGpTM not good enough?''

*  I kind of meant "runs-live-in-browser", not a movie of a client.

* ''Oh.  You kind of should have said that.''

Is it really fat-client or complicated-client in disguise?

''Neither, really.''

I'd like to see something like web-based VB-classic: click and drag and set properties.

''Sounds like a great idea for a Google App.  Let us know when you've got it working.''
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See http://code.google.com/appengine/ for more information.

See also CloudComputing