I'm trying to figure out the generic name for systems that allows users to contribute with the development of new features. Kickass Torrents has a very interesting app in it's site named IdeaBox and it's divided in stages such as: suggestions, planned, in progress, completed. It has a voting feature for everyone with more than 100 reputation and that's pretty much all. I wanna look at opensource alternatives but that's not possible if I don't know how it's generically named.
I haven't seen any especially unique name for these, just them referred to as suggestion boxes.
All Our Ideas operates as a service, but the software is open and available on Github.
BBYIDX is a similar offering that oddly enough had its start at Best Buy.
If you want to get more hands-on, the WordPress Ideas(and Kvetch) areas are almost certainly built on WordPress, via some combination of user submission form, voting plugin and the built-in registration system.