ChameleON Social - Create your own dating site or social network
SocialEngine - Socialengine PHP: Elevating Your Online Community Experience.
vldPersonals - Full-featured PHP solution for running an online dating site.
mooSocial - mooSocial is the best social network script to create a niche community or social site.
Skadate - Skadate is a dating software.
JomSocial - Open Source Social Networking Software. Award winning open source community software by JomSocial. This social networking software is widely used by many Joomla users.