It depends on what you want to do with your startup. With App Engine, you're limited to Google's sandbox, that means that third party libraries can't be instal

It depends on what you want to do with your startup. With App Engine, you're limited to Google's sandbox, that means that third party libraries can't be installed, and Python has many, many third party libraries that make a developer's life so much easier. The initial example was PIL, or the Python imaging library, that a lot of web developers use to resize images for their sites. App Engine didn't support using PIL because it was a third party library, and when enough developers complained they opened up the API that's used for Picasa's web albums. Another issue that you might run into is merchant accounts and libraries for credit card purchases. You can't use them, and as of a month ago when I was looking at GAE, there was no solution.