Audacity is a cross-platform image editor available for GNU/Linux, macOS, Windows and more operating systems.
Audacity is free software and is the recommended way to edit sounds for Unvanquished.
The Audacity website is audacityteam.org.
The Audacity documentation is on audacityteam.org/help/documentation.
The Audacity source repository is github.com/audacity/audacity.