• BigTweet - BigTweet installs as a bookmarklet and allows you to post to Twitter from any web page. Choose a classic 140 character update, or a 240 character tweet. Insert special Unicode characters and shorten URLs with the Bit.ly API right from the bookmarklet window. Automatically capture the current page title, URL and any highlighted text. No registration is required - only Twitter login credentials are needed.
  • BLT — twitter meets the Bourne shell, with a hint of biff.
  • feedalizr - A free deskptop application that allows you to view, rate and comment on what your friends are sharing online. Tweet, upload pics to Flickr, update your Facebook status, keep up to date with your friends’ Google Reader, Digg, Tumblr, YouTube and Last.fm posts on Friendfeed. Use unique filters to reduce the noise. Duplications are filtered out. — by MIH SWAT
  • GtkTwitter — a Twitter client for Linux and Windows which using GTK.
  • Gwibber — an open source microblogging client for GNOME developed with Python and GTK. It supports Twitter, Jaiku, Identi.ca, Facebook, and Digg
  • gTwitter — a Twitter client for Linux.
  • KickTweet — A very simple KDE Kicker panel applet.
  • ktwitter - A simple Twitter script for KDE.
  • mitter — A very simple Python and pygtk client.
  • Qwit — A simple Qt4 based crossplatform client.
  • Twirssi - Read and Post tweets; Send and Recieve DMs; All from within irssi. Support multiple accounts, context fetching, replying to particular tweets.
  • Twit and Wayd — Two addons for Gnome Deskbar that allow posting updates to Twitter
  • twit.el Another Emacs client.
  • Twitbar — a Twitter client for Gnome users to post from the Deskbar
  • twitter.el Twitter from Emacs!
  • Twitux — a Twitter client for the Gnome desktop. Features includes: gui-notifications, url tinyzer, and more..
  • Vim Twitter Twitter from Vim!
  • ZenTwitter — bash script which uses zenity and curl (could be launched from custom desktop/menu/panel icons)