Gwibber - Gwibber is an open source microblogging client for GNOME developed with Python and GTK.
Tweetium - Tweetium is first and foremost designed to be quick and reliable.
Socialite - History Ever since we acquired Socialite from Realmac Software in December 2010, we have been planning on releasing a faster, more stable version 2.
HootSuite - Enhance your social media management with Hootsuite, the leading social media dashboard. Manage multiple networks and profiles and measure your campaign results.
Earthquake - Terminal-based Twitter Client with Streaming API support. Only supports Ruby 1.9 and later.
TweetDuck - Free & open source desktop client for TweetDeck