Audacity is a free audio studio for the recording, editing and playing of audio files. It supports the most popular formats (MP3, Ogg/Vorbis, WAV, MIDI, AIFF). You can mix music tracks, add sound effects, convert audio files or change the playback speed.
The recording feature enables you to capture all the audio signals and save them to the hard drive. The noise filter can quickly get rid of any disturbances.
Note: A Linux and a Mac version are available to download.
For version 2.0.3 another resampler was integrated that's supposed to be faster. Numerous little bugs have also been fixed. All the other changes you can find in the release notes of the manufacturer.
Verdict: A wonderful audio studio for your PC. The long development time shows very positively, there probably isn't a more mature free audio editor and recorder available to download.
Supported formats: AIFF, ADPCM, AU, IRCAM, MP3, OGG, WAV.