Arch Magic by Mayfair.

If your in a gaming store that has old Role Aids products and see a box
called Arch Magic by Mayfair (now out of print)....Get it!  It has some GREAT
stuff that can be adapted to Spelljammer.  The Macrodrome is a gnome-like
race that have recreated a barn-sized model of a world and play war-games
using monitor lizards that move the pieces around.  You have to see the
picture to understand, but it is bizarre.  Then next section is my
favorite... The City of Bone.  It looks like a (miles long) space beast
skeleton that a city has been built in.  I use is as a major
illithid/neogi/drow/Antilan/ undead/beholder trading center.  Raharrow's Lair
is a strange dungeon lair, but has a great picture of what I envision the
Syllix should really look like (and one of their worm-cavalry also).  The
Gibbering Cavers is a  dungeon that looks more like someones intestinal
track.  It is the most alien (disgusting) setting your players could ever
wade through.  There are several mundane maps and adventures (one with a
mechanical dragon).  But the above mentioned picturers are worth it.  BTW,
they are three page fold-outs.

Terry