FLAC stands for Free Lossless Audio Codec. Grossly oversimplified, FLAC is similar to MP3, but lossless, meaning that audio is compressed in FLAC without any loss in quality. This is similar to how Zip works, except with FLAC you will get much better compression because it is designed specifically for audio, and you can play back compressed FLAC files in your favorite player just like you would an MP3 file. Changes:

Updated .exe files for FLAC v1.1.1
Will now installs/update flac.exe and metaflac.exe in the System32 folder (useful for SHNtool)
Updated Winamp2/5 FLAC plugin to official v1.1.1 release (improved configuration options)
Updated Foobar2000 FLAC Decoder Plugin to v1.0.16
More sane Frontend defaults
Upgraded installer to NSIS v2

Download: FLAC 1.1.1