SourceForge

If you're not familiar with SourceForge, it's one the largest open-source project hosting sites on the Internet.

You can find nearly any kind of software there, from very useful programs, to the irrelevant.

You can link to the site's search page using the following address:

http://sourceforge.net/search/?type_of_search=soft&type_of_search=soft&words=Framework

(you can replace Framework by your desired keyword)