Software for brainstorm / ideas sharing and voting?

Some time ago, Ubuntu had Ubuntu Brainstorm, a website where non-developers could submit ideas of improvements, and other people could comment and vote on them. I was wondering if there was existing software to deploy a similar service, e.g. as a plugin to popular forum software. I’ve found, but relying on the Cloud for that is not acceptable for my planned use.

(For clarification: my immediate interest for that is unrelated to Debian work)