If you are on App Engine though chances are you will use the other APIs like the...

sprite on July 24, 2014 | parent | context | favorite | on: Open Source Implementation of Google App Engine

If you are on App Engine though chances are you will use the other APIs like the Taasks API. If you run your own software stack instead you can move it wherever without rewriting any code. With App Engine you either rewrite your code or use app scale.

abritishguy on July 24, 2014 [–]

But you don't have to use those!