Swivel - Adobe Flash renderer for creators developed by Newgrounds.
BuddyPress - WordPress social networking in a box.
Bigcolors - Create, invest & trade startups
Elgg - Opensource social network engine
Free SWF to Video Converter - It is an easy-to-use tool to convert Flash to AVI, FLV, WMV, MOV, MPEG, MP4, 3GP, MP3, Animated GIF, BMP, JPG, etc.
SocialEngine - Socialengine PHP: Elevating Your Online Community Experience.