calibre is a free and open source e-book library management application.
Convert LRF (Sony BeBB) files to EPUB, PDF, RTF, and HTML. Also converts PDF and DOCX to EPUB.
Convert CSS Snippets to Syntactically Awesome StyleSheets code
flv converter - transcodiert (!) nach mp4 oder avi
Yacufs depends on FUSE. It allows for the on-the-fly transcoding of various file formats. It is highly configurable.