LameXP - LameXP is an Audio Encoder Front-End, a graphical user-interface for a number of audio encoders.
winLAME - winLAME is an encoder for several audio formats, including mp3 (MPEG Layer 3), Ogg Vorbis and more.
FLAC - A free, open source codec for lossless audio compression and decompression
Format Factory - Format Factory is software that allows the user to convert media into various file formats. The software is a product of PC Free Time, a Chinese software development company. Read more about Format Factory.
WavPack - WavPack is a completely open audio compression format providing lossless, high-quality lossy, and a...
FLAC Frontend - [No longer maintained, but downloadable]