Ardour is a free, open-source program that enables professional sound production, from recording single tracks through mixing and editing to film sound. The program is being developed for Linux and OS X, and with version 4.0 there are test compilations for Windows. Ardour is a very flexible program.

During recording it is able to capture sound (including MIDI) from any device (PCI, USB, FireWire, network...), as long as it is supported by the operating system. The developers also boast of the industry's best LTC and MTC synchronization. Track recording is basically unlimited - they can be mono, stereo and multi-channel, but recording of all tracks is trivially simple, but the flexibility of editing and mixing channels has been retained.

Import of tracks and samples is possible using a huge range of formats, and for OS X also Garage Band and Apple Loops collection resources. The Freesound library is also easy to access. Editing the recordings allows for non-linear and non-destructive actions, and at the same time the history has no limits, so you can "go back" to your heart's content, even after closing and reopening the session.

All operations are performed in one window, without switching between pallets. If the fragments overlap, they will be presented as transparent or in the form of a vertical stack for better readability. While working on the soundtrack of films, you can quickly import the film and extract the original soundtrack from it, and during editing, you can preview the image frame by frame.

Ideal synchronization is ensured by the possibility of anchoring sound fragments to the image, with the accuracy of single frames. Ardour is a free and open program, but not free. You can already have it for one dollar, buying it on the project website.

Demo version available for free allows you to work for 10 minutes, then stops making any sounds. You can then continue working in silence or save the project.