anyone know of an open source social network/collaborative platform?

[Gato Moteado]

I want to grow my network of people interested in preserving the rain forest. I created a facebook group for this but not everyone in my network is on facebook. i'm wondering if there's an open source collaborative platform out there that I can install on my host that will allow people to create conversation threads similar to facebook.

anyone know of any?

[kydo]

1. this probably should be in the website db forum

but try this these

https://www.phpbb.com/ I like this one

http://www.phpjunkyard.com/php-message-board.php

[Gato Moteado]

2. Thanks!

yeah, I considered phpbb or SMF but i'm not sure if everyone would be into the idea of a forum (though, I like them). I think what I need is something similar to what facebook does...someone posts a topic and the whole thread can be seen at a glance. but, if there's nothing like that out there, i'll probably go with a forum.