What's different about Google Apps?
Four important things. Here's the first:
1) Currently, the only language supported is Python.

That's good news and bad news:
The bad news is, of course, that a lot fewer people can write Python programs, and there aren't many existing financial applications written in Python. There are, however, a lot of non-financial applications in Python, in sophisticated areas such as language processing, computer games, and even computer animation. "Every CG image we create has involved Python somewhere in the process," said Philip Peterson, Principal Engineer, Research & Development, Industrial Light & Magic. (as quoted on the Python website) The good news is that Python is a really nice language. Try it: you'll like it. The Google development team tried it, and they like it enough that they use it extensively in-house. They liked it enough that they hired the person who created Python, Guido Van Rossum. See his his personal web page, with a brief bio, on http://www.python.org/~guido/.

I wrote another blog article about Python here.