UX2 on Linux? No, unfortunately the only thing im aware of is the following,

http://www.tanzband-scream.at/line6/

its for the pod series, one specifically. The UX2 doesn't seem to have much any support in linux, community or otherwise.

I just recently purchased the UX2 which will probably be my first and last purchase of any line6 hardware. Dont get me wrong, its great for what it is, and the included guitar vst plugin is nice, but I do a lot of hacking on various OS's working with sound and I have my doubts now that any line6 products fulfill that niche.

I bought this to replace a broken Edirol UA-25 (that someone decidingly crammed into a closet with the usb cable still attached damaging it pretty badly) and comparitively, for the extra $40 the roland costs, its well worth it. Linux support out of the box, no messy driver installs, using jack sound server right away, has MIDI support and numerous other features lacking on the UX2. Selecting the same sound options latency-wise for each respectively, I noticed the UX2's latency was worse then the edirol and also a bit buggy with not updating latency times correctly in ableton sporatically and when doing so would feature ridiculous latency times of 40-90ms. Once it start working right it seemed solid though.

Also, this may be unrelated but the UX2 seems to have problems with a software mixer i am writing ( which can be seen here: http://vizi.dasa.cc ) with numerous buffer errors that i never experienced with the edirol ua-25. Regardless, ill probably keep this thing long enough to track down the error with the hardware to patch my program, and long enough to make a few jams in ableton, but this thing will definately end up on ebay. Just isn't for me.

And now for a positive word, Ive written this as information for anyone doing research on the UX2 that has similar interests as me (software, linux, guitars, etc), when doing research beforehand (quite short-lived too) I couldn't really find what I was looking for and decided to dive right in to get experience with line6 products. My take-away from this is I might recommend line6 to anyone non-technical as they really give you everything out the box to kick you into gear and for one hell of a price at that. The included guitar modelling software is quite good and gives you alot of versatility. A similar product I've used is Guitar Rig 3 (which is pricey in its own right) and after warming up to the line6 vst for an hour, i honestly dont really feel like i have a preference. I didn't really get into the details of the line6 vst but i didn't really have to, I was pretty happy with most of the defaults.

HWAET, point being line6 does rock but its not suited for me. Enjoy!