Twitter

Pwytter - Cross platform Python Twitter client with Asian character support.

Teletwitter - Experimental open source client.

TwitBox - View and submit tweets, see replies and direct messages, delete your own tweets, and multiple account support.

Twitterlicious - Update Twitter status, easily check replies and direct messages.

Twitteroo - Client with rurl URL shortening, clickable links and tweets, customization, and both public and friend timelines.

Chirrup - Twitter client with extensive Japanese language support.

TwittIt - Extremely compact and simple app for submitting tweets.

MadTwitter - A reincarnation of Twitterrific, except on Windows.

Twitter CLI - Post tweets via the command line.

What’s Up? - Gadget that allows you to see latest tweets from your friends.

Twadget - Simple gadget that lets you view and submit tweets right from Vista’s Sidebar.

KipFolio Widget - Simple Twitter widget for KipFolio.

Twitter-Sync for Yahoo - Syncs Twitter status with Yahoo Messenger status.

TwitterYM - Simple Yahoo Messenger status updater.

Twessenger - Updates Live Messenger status to reflect latest tweet.

Twit4Live - Set status message as latest tweet, send tweets from within Live Messenger, and send tweets to contacts.

Twitterrific - A compact client that publishes tweets, shows unread tweets, has easy access to profile pages, shows either public or friend timeline, and more.

TwitterPost - Basic client that submits tweets, shows your current iTunes track in your feed, and more.

Twitgit - Read your friend’s tweets and submit your own, right in Dashboard.

TweetAhead - Schedule tweets to be posted ahead of time with a simple Dashboard widget.

Twitterlex - Dashboard widget that shows your friend’s latest tweets as well as allows you to submit tweets.

Twidget - Update your Twitter status within Dashboard.

TikiTwit - Match your iChat status to your last tweet.

BLT - Perl script that lets you see what your friends are doing right from the Terminal.

Twitter for Vim - Publish tweets right within Vim.

ZenTwitter - A GUI frontend for Twitter using zenity and curl.

Twitux - Twitter client for the GNOME desktop.

gTwitter - GTK+ based app inspired by Twitterrific.

Twitter.el - Publish tweets while in Emacs.

Twitbar - Post tweets from the GNOME deskbar.

Twit.el - Another utility that allows publishing of tweets within Emacs

Tweetr - Submit tweets, upload files, urltea built in, delete messages.

Spaz - Cross-platform client built with AIR.

Tweeter - Java based client with customizable UI.

Twinja - AIR based client which allows you to follow users on the fly.

TwitBin - Send and view tweets right within Firefox.

TwittyTunes - A FoxyTunes addon that posts what you’re currently listening to Twitter.

Shareaholic - Share links and webpages via Twitter right within Firefox.

Search Plugin - Tweet right from the Firefox search box.

Tweetbar - Put Twitter on your Firefox sidebar.

Twippera - Twitter widget for Opera that can send and view tweets.

TwitterFox - Compact Firefox extension that can publish and view tweets.

iTweet - A mobile Twitter site designed for the iPhone.

iTwit - Mobile version of Twitter made for the iPhone.

Tweeter - Twitter on your mobile phone while avoiding text message charges.

Jargong - Browse Flickr, do some social networking, but most importantly, check and publish tweets.

WildSets - Extensve Twitter app for mobile phones.

TwitterBerry - Twitter built for various BlackBerry devices. Update and view timelines with ease.

jTwitter - View timelines, enter updates, and more, all on your mobile phone.

TreoTwit - Easily check and update your Twitter right from your Treo.

Twittervision - See where in the world people are submitting tweets from, real time.

TwitThis - Allow visitors to your site to easily share a page or post via Twitter.

MoniTwitter - Receive important updates about your site via Twitter.

TwitterNotes - Share private or public notes via Twitter.

RSS2Twitter - Share any RSS feed on Twitter, and have new RSS items automatically be tweeted.

TwitterBuzz - Find out what is being most linked to on Twitter.

Twitterholic - Shows the top users and accounts on Twitter.