Mobipocket DRM Removal is a commercial tool that allows to remove DRM from Mobipocket ebooks.
Haven't tried to use it, since freeware Mobipocket DRM removal plug-in for
Calibre works just fine. Besides Calibre can convert Mobipocket files to other ebooks formats, so you can read Mobipocket ebooks whether you use
Kindle,
Sony Reader,
Nook or some other reader.
Download Calibre DRM removal plug-ins:
ebook DRM removal tools archive