Laconica – The Open Microblogging Tool
http://laconi.ca/

Laconica (pronounced “luh-KAWN-ih-kuh”) is a Free and Open Source microblogging platform. It helps people in a community, company or group to exchange short (140 character) messages over the Web. Users can choose which people to “follow” and receive only their friends’ or colleagues’ status messages. It provides a similar service to sites like Twitter, Jaiku, and Plurk. This has been added to World Wide Web Reference Subject Trace™ Information Blog. This has been added to the tools section of Research Resources Subject Tracer™ Information Blog.