From the website:
IdeaTorrent is what can be defined as an “open innovation software”: it lets people submit their ideas, brainstorm them, and vote on them. The most popular ideas and requests are then easily accessible. That’s a very interesting mean for a project to have an insight on the demands of his user base!
What does it offer?
IdeaTorrent includes multiples solutions to a single rationale support, strong community based moderation tools, theming support, and is based on Drupal. See the demo! It is a Free Open Source Software (FOSS) licensed under GNU General Public License, which means you can freely download it, modify it and distribute it.
IdeaTorrent is open-source and its source code is on Github.
Update: IdeaTorrent has been discontinued. In order to access the site, view an archived copy.