Kunena is the leading Joomla forum component. Downloaded more than 4,000,000 times in 6 years, Kunena is the only forum/discussion solution for Joomla that is community driven - true open source - public self-help forums, GitHub and documentation Wiki.
The most recent stable release, recommended for production websites running J! 2.5 and J! 3.x, is Kunena 3.0.6
Details about Kunena 3.0.6 are contained in the release notes at http://www.kunena.org/docs/Kunena3.0.6Read_Me
For more details about the extent of Kunena features see http://www.kunena.org/docs/Kunena_Features