BuddyPress.org

@Andrea I installed it about a month ago. The problems I had were numerous.

1. Thumbnail generation did not work due to the classic blog.dir/blog-id/ with mu issue.

2. Whenever I would upload images/files/digital downloads/anything I would end up with the red bar with nothing there.

After their absolute disgusting way of dealing with customers, I gave up at that point. (basically told it does not support mu, no refunds, take a hike).