Ardour is a full-featured audio mixer and editor with unlimited tracks and non-destructive editing, patching and routing, video sync for soundtracks, and plugin support for AudioUnits on macOS, VST on Windows and Linux, and LV2 on all platforms. Automation is possible with Lua scripting. It is an alternative to the popular Audacity, another cross-platform audio editor, but Ardour has a more complete set of features for audio engineers.
The result is full latency compensation so that alignment of the various signals routed through Ardour is precise. There is also a new resampling engine, the ability to add sound effect processing to a track when recording, simultaneous monitoring of input and output, improved MIDI support (though there remains "significant work to do"), and an enhanced plug-in manager.
On the audio format side, FLAC is now an option for Ardour's native recording format, and MP3 import and export is now fully supported – the developers were formerly opposed to MP3 import because it is a lossy format and not intended for this use. There are hundreds of other new features, and experimental support for a web browser user interface using WebSockets.
See Ardour goes harder: v6.0 brings 'huge engineering changes' to open-source digital audio workstation
Dev sticks with elderly GTK+2 GUI toolkit because 'we would gain nothing' by upgrading