*. Supports MP3, OGG Vorbis, WAV and AIFF.
*. Live recording.
*. Encode audio tracks with various changes (low/high bit-rates, etc).
*. Edit - Cut, Copy, Mix tracks graphically.
*. Add effects.
*. Change pitch or speed settings.
*. Record up to 16 channels at once.
*. Play files reversely.
*. Load Raw audio files.
*. Various audio analyzing methods (Spectrograms, etc).
So, if you run Ubuntu and want to install Audacity using daily build PPA channel, then open the Terminal and issue the below command.
sudo add-apt-repository ppa:audacity-team/daily
sudo apt-get update
sudo apt-get install audacity