- TwitterScript by Michael Galpin. AS3 API, originally from Twitter, now open sourced.
- SWX Twitter API by Aral Balkan.
- QTwitLib by Bradley Lackey & Maks Zolin. C++ library for Linux, Windows, and Mac. Currently in beta.
- Yedda Twitter Library by Yedda. Every Twitter API method has an equivalent .NET method in this wrapper library.
- TwitterooCore API by Eric Willis/RareEdge Design Group. Binary .NET library that can be used in any .NET project.
- Twitterizer originally by DigitallyBorn, but now open source. Written for .NET 2.0.
- tweet# by Daniel Crenna. “100% coverage of the REST and Search APIs”.
- Twitter4J by Yusuke Yamamoto. BSD licensed and Maven aware pure java interface for the Twitter API.
- java-twitter by DeWitt Clinton. Pure java interface for the Twitter API.
- jtwitter by Daniel Winterstein. Open-source pure Java Interface to Twitter.
- MGTwitterEngine by Matt Gemmell. Integrate Twitter support into your Cocoa app.
- App::Tweet by Joshua McAdams. Tweet on Twitter from the command line.
- Net::Twitter by Chris Thompson. Perl interface to Twitter.
- Twitter::Shell by Daisuke Maki. Twitter from your shell.
- My Twitter by Andres Scheffer. Set and retrieve a Twitter user’s status.
- Twitter by Felix Oghina. Update the status of a Twitter user.
- TwitterLibPHP by Justin Poliey. Manipulate a Twitter user account.
- Arc90_Service_Twitter by Matt Williams. Open source Twitter API client.
- PHP Twitter by Aaron Brazell, original code from David Billingham.
- PEAR Services_Twitter by Joe Stump and David Jean Louis.
- PHP Twitter by Tijs Verkoyen. BSD Licensed.
- OraTweet by Noel Portugal. PL/SQL procedures to get friends timeline and post updates.
- python-twitter by DeWitt Clinton. This library provides a pure Python interface for the Twitter API.
- python-twyt by Andrew Price. BSD licensed Twitter API interface library and command line client.
- twitty-twister by Dustin Sallings. A Twisted interface to Twitter.