Teambox is a project management platform created for real-world, real-time collaboration. Teambox uses a Twitter-style means of communication to send messages, update project status, and manage assigned tasks.

PeoplePods is an open source SOCIAL NETWORKING twitter clone toolkit built with PHP/MySQL for creating websites with social networking capabilities with ease. It can be used to build stand-alone sites or layered onto existing sites for adding social functionality.

OpenMicroBlogger is a oPEN SOURCE TWITTER CLONE. It’s different from Laconi.ca because it’s easier to install and it adds Movie/Photo/Song uploads (though the content does not broadcast to subscribers on other sites, just the notice itself and its original URL)

Sharetronix Opensource is a multimedia microblogging platform. It helps people in a community, company, or group to exchange short messages over the Web. Very similar to Twitter, users can easily connect with each other with open or private threads.

I. Create your activity stream
    * Post new Jaikus
    * Add icons
    * Customize your background
    * Add your Web feeds
    * Set your location
    * Put a Jaiku badge on your blog

P2 is a theme for WordPress that transforms a mild-mannered blog into a super-blog with features like inline comments on the homepage, a posting form right on the homepage, inline editing of posts and comments, real-time updates so new posts and comments come in without reloading, and much more.

A group blog theme for short update messages, inspired by Twitter. Featuring: Hassle-free posting from the front page. Perfect for group blogging, or as a liveblog theme...

General Features - Secure Login Optional Email Validation Optional CAPTCHA Registration Friends List Replies and Mentions Direct Messages User Customizable Public Profiles Comments Email Boxes Limited Mobile Messaging Support Emoticons Hyperlinking User...

NoseRub only defines the social network and some basic content types like media, links, micropublishing and text. You can now add all your contacts to a NoseRub network and aggregate several social networks into just one.