Moving 2D raster graphics ("sprites") on Suns

[Jim McCabe]

I'm looking for the source code to some programs that use what some people
call "sprites", for a cute graphics demo I'm writing.  I have looked for
the source code to Asteroids (gasp, a game) for this, but can't find it
anywhere.  (I'm told uunet has it, but I can't seem to connect lately.)

So, specifically:

*  Are there any public domain sprite-manipulation libraries?  If so,
   where?
*  Are there any PD programs out there that would make good learning
   examples for sprite usage?  Where?  Etc...

I realize that I'll probably be using typical memory pixrects, but I would
love to see an example program that uses them extensively as an extra
guide.