Synergy is a tiny Cocoa application for Mac OS X 10.2 (and later) that puts three buttons to control iTunes in your menubar: previous track, next track, and play/pause. It also provides you with visual feedback about the currently playing tune and allows you to control iTunes via system-wide hot key combinations. These features provide a very fast way of skipping between songs when using the keyboard or the mouse, without having to switch to iTunes or access its Dock menu.
TwistedWave is a very easy-to-use and powerful audio editor. It supports Audio Unit plug-ins and many file formats, including wav, aiff, caf, mp3, mp4, FLAC, and Ogg Vorbis. It has good multichannel support, so you can apply Audio Units to a selection of channels. It supports unlimited undo and redo, which work instantly. Zooming in and moving around the waveform is very fast, even with very large files. All the effects are applied in the background, saving a lot of time.
CastCluster provides access to additional content on iTunes, Apple TV, iPod, or a random podcast viewer. It currently supports YouTube, Google Video, Revver, local disks, and RSS feeds as sources of content. It uses ffmpeg for video conversion. It also provides some other bookmarklet functionality, like digg and del.icio.us.
Phelix is a duplicate file removal tool with an acoustical audio matcher. Duplicates with bad or missing music tags but the same or similar sound will be detected by the matcher, even if audio signals are shifted, start at different moments, are ripped with different bit rates, or are ripped with different volumes. It is designed to work well on multi-core systems. Files are never deleted, but are moved to another directory for inspection.
EasyPMP is a program used to create and maintain the music database on a variety of portable music players. This allows tracks to be browsed by artist, album, genre, etc., rather than by directory structure. The following devices are supported: iRiver H100 series; iRiver H300 series; iRiver H10 UMS; iRiver H10 MTP (with emergency connect mode); iRiver H10Jr. UMS; iRiver U10 UMS; MEDION MDJuke220 and MDJuke 440; and Samsung YH-820, YH-920, and YH-925. It is developed as part of a project called PMPlib, which aims to develop a library that can be used by desktop media players and other programs, in order to support these devices.