Wikipedia
Qtractor
Qtractor is a hard disk recorder and digital audio workstation application for Linux. Qtractor is written in C++ and is based on the Qt framework. Its author is Rui Nuno Capela, who is also responsible for the Qjackctl, Qsynth and Qsampler line of Linux audio software. Qtractor's intention is to provide digital audio workstation software simple enough for the average home user, and yet powerful enough for the professional user.
Qtractor is currently under rapid development, and Git versions are updated often with new features.
Released under the terms of the GNU General Public License, Qtractor is a free and open source software application.