costwish is a tool for postprocessing and rendering of SGML documents based on Joe English's impressive CoST tool. It's based on tcl/tk and runs on all UNIX boxes; I hope that with the tcl/tk port to MAC and PC it will soon be available there.
The costwish distribution contains all the material to build and/or install it, but there is also a lot of generic SGML information, especially aimed at those new to SGML. So even if you don't want to run costwish, I hope that the material here might be useful.
There is a huge amount about SGML on the WWW and most can be easily found from the links below.
PeterMR
April 21 1996