The IBM AIX Service FixDist server
- providing AIX PTFs along with a GUI Motif interface for managing them.
The IBM T.J. Watson Research Center - has AIX Level 2 Security fixes along with a host of research and files relating to other IBM products.
AIX Public Domain Software Library - has probably the largest collection of binaries and ported source code for freeware/shareware applications for AIX on the Internet.
FUNET - a humongous Anonymous FTP site and serves as the home site for the freeware monitor performance monitoring application by Jussi Maki.