It's been a long time since I worried about this, but I'll bet you could roll your own without too much trouble. You can use a large, flat file (which you mmap() into memory) for storing your textures. You just lay them out sequentially in whatever format your graphics library calls for. The only trick is that you need a table somewhere that tells you the offset, size, and so forth of each texture tile. Given that, you can figure out the offset and convert that to a pointer of the appropriate type. (Let's hear it for C and C++'s ability to casually convert types back and forth.)