If you want to do it yourself:
First I set CFLAGS to "-fsigned-char -fpack-struct -O3 -funroll-all-loops
-fPIC -ffast-math -fomit-frame-pointer".  Then I ran configure with
"--host=arm-linux --enable-quad-scanline".  You can get the source at
http://www.muppetlabs.com/linux/descent/ but it doesn't have my fixed-point
patches yet (they give a very noticable speedup on the NW).  Also, the only
files you need from your DOS installation of Descent are chaos.*,
descent.pig, and descent.hog.  Happy Descenting :)

Notes on this version:
- The patch for the fixed-point stuff isn't in 0.0.19, but it should be in
  0.0.20.
- Same thing goes for the patch for SVGALIB support.  Though I had to
  screw with asm/io.h for it to work.  I don't think it works 100%,
  though, since it'll only do 320x200.