Audacity

Audacity records from a microphone or line input and edits the result on a multi-track timeline. The everyday work it is used for is narrow and well covered: trimming takes, levelling volume, removing hum and background noise, applying fades, and exporting to WAV, FLAC, MP3 or Ogg.

Editing is destructive by default but every step is undoable, and the spectrogram view helps when a problem is easier to see than to hear. The effect list includes compression, equalisation, noise reduction, pitch and tempo change, and the same effects can be applied to a batch of files through Macros. LADSPA, LV2, VST and Audio Unit plug-ins extend the list.

Audacity has been developed since 2000, is currently maintained by Muse Group, and ships for Windows, macOS and Linux. It suits podcasts, voice-overs, lecture recordings and archival transfers more than it suits full music production.