Links

Unofficial Packages

Ubuntu
Gentoo
Arch Linux: x86 x86_64; Install with pacman -S xwax

Audio interfacing

The MsPinky forums are a good place for cross-platform audio interface and preamp discussion
ALSA project: development of Linux audio drivers
Mark's Soundcard resources for Linux DJs

Coverage

DJworx: PiDeck: DVS and touch screen for your turntable
createdigitalmusic.com: Vinyl Scratching Emulation on Linux
djforums.com: Xwax - An open source DVS
Skratchworx: And for Linux users...
Vinylproject: The Sour Taste of Humble Pie
foss.in 2008: photos 1 2 3
New York Linux User's Group: November 2008

Projects using xwax

PiDeck: Putting embedded GNU/Linux and open source DVS into turntables
Mixxx: open source DJ software for Linux, Windows and Mac; uses xwax for vinyl control
xwax setup at gas-werks
disko
vinylcontrol: pd max/msp patch based on xwax

Other open-source software

Digital Scratch is a basic library reading a Final Scratch timecode
bpm-tools for automatically calculating BPM of music and tagging files
key-tools is a simple command-line tool for key detection, based on Imrahim Sha'ath's excellent KeyFinder GUI software

Related projects

Cleanfeed is an easy-to-use live audio link in a web browser, aimed at broadcasters, podcasters and more
trx is a configurable Linux tool for production audio-over-IP links, such as transmitter links or outside broadcasts
File Detective is an online tool for identifying files and displaying detailed information of the codecs in use

Historical interest in Digital Vinyl

Software/setups for other platforms

Final Scratch (Wikipedia): an overview of all versions of Final Scratch, including the original Linux release (now obsolete)
Stanton Final Scratch v2
Rane/Serato Scratch Live
Rane Rane SL 3 / Rane SL 1
Native Instruments' Traktor Scratch Pro
MsPinky, includes Windows SDK
MixVibes