Audio hardware support
Ardour doesn't use any audio device directly. Ardour accesses the audio interface through a program called Jack (http://www.jackaudio.org). This means that Ardour will work on any hardware which works with Jack.
Jack is created for posix compliant operating systems. Currently it's mostly used on Linux and OS X.
On OS X, Jack works with any CoreAudio supported soundcard.
In Linux, support for Jack comes through different audio driver layers.
- ALSA http://www.alsa-project.org (default Linux sound driver)
- FFADO http://www.ffado.org/ (Firewire driver, ex freebob)
- OSS http://www.opensound.com/ (commercial)
To check compatibility for a certain sound device, refer to the driver documentation. Most common audio devices are supported by ALSA. Firewire devices are supported by Freebob.
Freebob support is not built in by default into Jack, so you might need to follow documentation available at Freebob's and Jack's websites.