Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.

AudioMass - A full-featured web based audio editor 🎶

Spek - Spek helps to analyse your audio files by showing their spectrogram.

GoldWave - GoldWave. Digital Audio Editing Software. Record • Restore • Convert • Analyze. Fully loaded to do everything from the simplest recording and editing to the most sophisticated audio processing, restoration, enhancements, analysis, and conversions.

SoX - Sound eXchange is a command line utility that can convert various formats of computer audio files...

Wavosaur - WAVOSAUR is a free audio editor for Windows with VST plugins support. The program is ASIO compatible, can do loop points edition, auto-trim, noise removal.