Hitking
uddeIM 
uddeIM allows users of your community to send Private Messages to each other (note that uddeIM is not a webmail component nor an email client). uddeIM wants to be simple and easy-to-use but it offers all the features you need in a Private Messaging System ...
JComments
The JComments is a powerful and easy to use AJAX based comment system for Joomla with flexible ACL, smiles, BBCodes and avatars support. Working on this release took extra eight months, all this effort was spent to make the component more stable and usabl ...
Kunena
Kunena is the leading Joomla forum component. Downloaded more than 3,000,000 times in 4 years since its start, Kunena is the only forum/discussion solution for Joomla that is community driven - true open source - public self-help forums, GitHub and docume ...
K2
The powerful content extension for Joomla!, awarded "Joomla! component of 2010" at J and Beyond (the international Joomla! conference). --- WHAT IS K2? --- K2 provides an out-of-the box integrated solution featuring rich content forms for items (think ...
