Google App Engine has a few big services built on top of it: http://www.quora.com/What-are-the-biggest-sites-built-on-top-of-Google-App-Engine http://www.quora.

Google App Engine has a few big services built on top of it: http://www.quora.com/What-are-the-biggest-sites-built-on-top-of-Google-App-Engine http://www.quora.com/What-are-the-biggest-sites-built-on-top...