ffmpegX is a Mac OS X GUI designed to easily operate more than 20 powerful Unix open-source video and audio processing tools, including ffmpeg, mpeg2enc, and mencoder (the MPEG-4 encoder with subtitles support). ffmpegX includes a bitrate calculator, a video player, and a series of video tools which can split, join, or fix video, compress a DVD to 4GB, author many VCD/SVCD images into one DVD image, and convert SRT subtitles to DVD Studio Pro 1.5 format.
MP3OCD is an MP3 categorization program written in pure Python. It differs from traditional MP3 categorization because it queries freedb.org to obtain information about a set of MP3s and automatically renames them to their appropriate names. It also sets up a set of symlinks to make burning easy.
ova is a convenient console frontend for ripping CDs and encoding MP3 and wave files to the Ogg Vorbis format. It is also able to query the CDDB given a CD (or saved CD discid) or several MP3/Ogg Vorbis/wave files (very useful for downloaded albums). Ogg Vorbis files can be tagged and renamed according to elaborate patterns.