Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.

Mighty Networks - Mighty Networks enables entrepreneurs, organizations, and companies to create and grow a community-powered brand.

DownToMeet - DownToMeet is a platform to organize, find, and attend group events.

Bigtent - BigTent is a web-based organization and communication portal for groups.

CooMeet - CooMeet is one of the best and leading next generation of video dating web-based application specially designed for those users who want to talk online to people they have never met.

Nabble - Nabble is a forum software that are embeddable and fully customizable with scripting language.