Audacity is a free software, cross-platform digital audio editor and recording application. It is available for Windows, Mac OS X, Linux and BSD.
Audacity was created by Dominic Mazzoni while he was a graduate student at Carnegie Mellon University. Mazzoni now works at Google, but is still the main developer and maintainer of Audacity, with help from many others around the world.
The latest release of Audacity is 1.3.12, a beta, released on 1 April 2010. As of 20 October 2009, it was the 6th most popular download from SourceForge.net, with 63 million downloads. Audacity won the SourceForge.net 2007 Community Choice Award for Best Project for Multimedia.

Features: Some of Audacity's features include:

• Importing and exporting WAV, AIFF, MP3 (via the LAME encoder, downloaded separately), Ogg Vorbis, all file formats supported by libsndfile library
• Versions 1.2.5 and 1.3.2 and later also support Free Lossless Audio Codec (FLAC)
• Version 1.3.6 and later also support additional formats such as WMA, AAC, AMR and AC3 via the optional FFmpeg library
• Recording and playing sounds
• Editing via Cut, Copy and Paste (with unlimited Undo)
• Multitrack mixing
• A large array of digital effects and plug-ins. Additional effects can be written with Nyquist
• Amplitude envelope editing
• Noise removal
• Audio spectrum analysis using the Fourier transformation algorithm
• Support for multi-channel modes with sampling rates up to 96 kHz with 32 bits per sample
• The ability to make precise adjustments to the audio's speed while maintaining pitch (Audacity calls it changing tempo), in order to synchronize it with video, run for the right length of time, etc
• The ability to change the audio's pitch without changing the speed

* Contains major features of modern multi-track audio software[12] including navigation controls, zoom and single track edit, project pane and XY project navigation, non-destructive and destructive effect processing, audio file manipulation (cut, copy, paste)
* Converting cassette tapes or records into digital tracks by automatically splitting one track into multiple tracks based on silences in the track and the export multiple option
* Multi-platform: works on Windows, Mac OS X, and Unix-like systems (including Linux and BSD), among others
o The latest stable version supports Windows 98/ME/2000/XP/Vista, but Windows 95 and NT are not supported. Windows 7 support is still provisional. For Windows 7, the developers recommend the latest 1.3.x Beta[13]
* Audacity uses the wxWidgets software library to provide a similar graphical user interface on several different operating systems.

Audacity can also be used for post-processing of all types of audio, including podcasts. It can be used for finishing podcasts by adding effects such as normalization, trimming, and fading in and out.[14]

It is currently used in the OCR National Level 2 ICT course for the sound creation unit.