I was collaborating with a friend on the early versions, to see if it could be commercialised to provide a "house" system for radio studios and clubs (much like the house provides CDJs or turntables). Today that's superseded by DJs bringing their own laptops, of course.
I don't know much about Mixxx these days; that project was always much better set up to grow through a range of contributors (eg. with its scripting engine). But I think it's technical architecture is probably quite different.
Whereas, xwax was designed from day 1 with the idea it was a realtime system with very tight latencies, taking input from one audio interface and responding to it on another. That was fun on Linux (and FreeBSD!) systems of the early 2000s.
Are you aware of Rasteri’s SC1000? It uses a magnetic rotary sensor with a modified version of xwax instead of time-coded vinyl. I wonder if xwax has support for other DIY jog wheel controllers? I didn’t see anything in the docs.
GitHub - rasteri/SC1000: An open-source digital portable turntablist instrument https://github.com/rasteri/SC1000/ « the scratch wheel is handled by an Austria Microsystems AS5601 magnetic rotary sensor »
The infinite music catalogue in digital format with the analogue feel of mixing vinyl is the perfect match for me. It’s been fun introducing friends to DJing by loading up anything they want into Rekordbox and seeing the delight on their faces after a first successful blend of their favourite music.