Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.
LMMS - Make music with a free, cross-platform tool
Spek - Spek helps to analyse your audio files by showing their spectrogram.
Reaper - Reaper is a focused digital audio workstation (DAW) developed by Cockos. In the creation of the software, the digital audio technology company intended to make audio editing accessible to the masses.
SoX - Sound eXchange is a command line utility that can convert various formats of computer audio files...
AudioMass - A full-featured web based audio editor 🎶