The Id3TagLib.Net library provides reading and writing of ID3v1, ID3v.2.3, and ID3v2.4 tags. It is written in C# with the .NET 3.5 framework. It can also be used with Mono-based projects.
ObjectAL for iPhone is an audio library that provides a simpler Objective-C interface to OpenAL and AVAudioPlayer for iOS developers.
A LiveCD for data backup and disk imaging.
A social networks visualizer for Linux.