AnimeList
Note: AnimeList is still buggy. I can't guarantee it works perfectly.
AnimeList is an desktop application for MynimeList.net written in Python (and PyGTK). It includes list management, a search function and more is planned. Like a torrent section, media player detection and automatic list updates. AnimeList uses the Unofficial MyAnimeList API, which is made by Chuyeow. And is a bit better than the official one. The unofficial API does not include support for mangas yet, but it is planned.
The first beta (0.2-beta1) is now released and available at files.61924.nl. Bugs can be reported at the AnimeList topic or by sending a mail to me. The latest source code can be downloaded from Github. And the manual includes all the installation instructions.
Installers for Windows and Mac OS X are planned, but since I don't have Windows or a Mac, I can't make these.