GWT, Sproutcore or Cappuccino

I am about to start a new webapp that will be running on P/GAE and reagarding the front end we would like to use one of the mentioned frameworks (GWT, SC, Cap). Which one do you think is the most developer friendly? It seems that Cappuccino looks stunning but you have to learn Obj-J. Sproutcore seems nicer (since there is only JS) but I could not say I am impressed with the docs plus some of the demos are broken. GWT on the other hand is very mature but I have the feeling that using Java may slow you down as you cannot use some of the JS quirks on the other han开发者_如何学Pythond there is vibrant ecosystem around it.

I think the answer depends on what type of developer are you?

For me, I'm comfortable with Javascript and like the ability to manipulate the browser DOM so that I can implement features that may not be in the framework. That's why I prefer Sproutcore.

Checkout http://www.infoq.com/news/2009/09/sproutcore-1-0.

I have to agree with you that documentation is limited. However, I've found wiki useful and the community really helpful.

GWT is a very nice choice if you're using GAE-Java because then you can develop server-side and client-side in the same language. If you're using Python on the server-side, you won't be able to use GWT's simple RPC calls to serialize objects to/from the browser. It's still a nice framework though.

GWT does allow you to write JS-native code if needed, so you can "use some of the JS quirks" if you need to.

One warning: GWT apps are totally AJAX, so they can't really be seen by search engines (a general problem with AJAX, not with GWT specifically)