This week's book giveaway is in the Java in General forum. We're giving away four copies of Think Java: How to Think Like a Computer Scientist and have Allen B. Downey & Chris Mayfield on-line! See this thread for details.
If you mean web frameworks, there is the Google App Engine itself. I'm not aware of any major frameworks, e.g., an equivalent of Django or Ruby on Rails, but there are many frameworks in development, see the Go Dashboard and scroll down to Web Libraries near the bottom.