Insightful, the creators of S-PLUS.
CANdiensten, the European S-PLUS courses center.

S-PLUS related books
Modern Applied Statistics with S-PLUS
S Programming
Regression Modeling  Strategies
Modeling Survival Data
Mixed Effects models in S and S-PLUS
Applied Statistics in the Pharmaceutical Industry
Environmental Statistics with S-PLUS

Other Links
s-news, the S-PLUS newsgroup.
ProbStatInfo,  the creator of EnvironmentalStats for S-PLUS
Frank Harrels S-PLUS links.
More S-PLUS links from the Insightful UK ofiice