BuddyPress.org

This thread is six months old, it’s been marked as ‘resolved’ so not many people are even going to click it open, and the fact that BuddyPress is covered by the GPL license, means any plugins that use BuddyPress will also be GPL. This means you can do whatever you want within the terms of that license. This means you can ‘fork’ the software and provide updated versions if you so want to.