What are the main differences between CLTL2 and ANSI CL?
Any online links / resources?
Bill Clementson has http://bc.tech.coop/cltl2-ansi.htm which is a repost of http://groups.google.com/group/comp.lang.lisp/msg/0e9aced3bf023d86
I also found http://web.archive.org/web/20060111013153/http://www.ntlug.org/~cbbrowne/commonlisp.html#AEN10329 while answering the question. I've not compared the two.
As the posters note, those are only main differences. The intent is to let you tweak your copy of cltl2 into not confusing you in any major way, but the resulting document should not be treated as standard.
Personally I didn't bother-- I use cltl2 as a bed side reading (Steele is an excellent writer!), to gain insight into various aspects of the language, and the process by which those aspects were standardized; lets me think in CL better. When I program, I reference HyperSpec exclusively.