I wanted to write an addon for a loooong time now, but now I finally decided to actually start with it. Looks like it isn't the best time to start with Ace... ;)
I tried to browse through some of the addons hosted here (especially the libraries and I guess there are also some development tools around), but it looks like that's not possible.
I clicked on Projects and searched for a "List by category" or something like that but couldn't find any. And going directly to wowace.com/categories/ doesn't return any results, it only shows that there are 54 categories. (I got that idea from clicking on the category link inside the Ace3 project and just removed the library part at the end).
Am I just blind and don't see the correct link or can't you list addons in a specific category right now?