microblog-purple supports 2 platforms, Windows and Ubuntu. However, you may compile it yourself on your platform. The first version is 0.1 came with load of features that you missed for so long.
I have just involved in new project called microblog-purple hosted at Google Code. It has such a bad name but its capability is promising. If you are using Twitter for a whlie, I guess you are waiting Twitter IM to come back. Without Twitter IM via Google Talk, there is no comparable and really usable Twitter client for any OS. The greatest feature of Twitter IM is responsiveness. I mean bi-directional highly responsible. Personally, I would love to type one tweet, press Enter, type another tweet, press Enter and so on without waiting or blocking even a second. microblog-purple now provides Twitter plugin that lets you tweet as fast as Twitter IM and configurable refresh rate.