OpenTween is an open source Twitter client with settings that offer many features and flexibility. In 2011 when Tween became closed source, it was created by forking. For the current development status, please refer to OpenTween-dev ML.
This project can also be found on GitHub.
==== Ver 1.0.5(2012/08/17)
* CHG: 「タブを固定」機能を「タブを保護」に名称変更
* CHG: 閉鎖された画像共有サービスbrightkite・picplzのサムネイル対応を終了
* FIX: UserStreamsの >突然の仕様変更< に対応