Tony Hammond, Timo Hannay, Ben Lund, and Joanna Scott of Nature Publishing Group contributed a long a detailed look at social bookmarking tools in the April 2005 issue of D-Lib Magazine. The article takes a look at the history of bookmarks and reviews nine social bookmarking tools.
The authors, Nature Publishing Group, created social bookmarks tool Connotea which was released under GPL today.
D-Lib Magazine is sponsored by DARPA.