Introduction

Audacity is a free, easy-to-use audio editor and recorder for Windows, Mac OS X, GNU/Linux, and other operating systems.

License

Audacity is free software, developed by a group of volunteers and distributed under the GNU General Public License (GPL). See License.txt for details.

Free software is not just free of cost (like "free beer"). It is free as in freedom (like "free speech"). Free software gives you the freedom to use a program, study how it works, improve it, and share it with others. For more information, visit the Free Software Foundation.

Programs like Audacity are also called open source software, because their source code is available for anyone to study or use. There are thousands of other free and open source programs, including the Mozilla web browser, the OpenOffice.org office suite, and entire Linux-based operating systems.

Understanding The Source Code

To understand the GUI parts of Audacity, you will first need to familiarise yourself with the wxWidgets toolkit. You will find The Shuttle System used very widely for user interface construction. See the classes in src/widgets for how we create new widgets of our own.

A great deal of the Audio processing in Audacity is done using libraries of code such as libsndfile and allegro. Some self contained audio functions can be found in src/effects, for example EffectEcho and its accompanying dialog EchoDialog.
The BlockFile system is central to how Audacity allows cut and paste of audio to be performed efficiently. It works closely with the DirManager class.

Also look at the overview pages in the Doxygen documentation, which cover special topics.