xawtv started as TV application for the bttv driver, because the Motif-based "xtvscreen" was the only TV application at this time. Alot has changed since:
The xawtv and bttv driver switched over to the video4linux interface.
Support for more interfaces was added: Xvideo Extention, the new video4linux2 interface and BSD Family video grabber driver (bktr).
xawtv isn't a single application any more, it is a small suite of video4linux related software, with video recording capabilities and serveral useful command line tools.
In the future even more hardware will be supported, the current development snapshots already have DVB support for example.
