PUBLIC MARKS from camel with tags free & "open source"

While large scale social sites like Flickr, Digg, Youtube and Myspace have predominated the web-o-sphere over the past few years there still is a need for narrow content verticals in this arena. This list will give you links to 40 open source resources to get you started building your own social bookmarking, networking, filesharing or search application. The following is a list of what I consider the be the best open source social software that I've found over the past year. Please let me know through email or a comment if you know of any other great social bookmarking, network, filesharing or search applications, and I'll be glad to post them. Also special thanks to all of the folks who produced all of this great free software. All descriptions below are taken from the developers of the software.