APL Organizations:special interest groups APL & J
ACM SIGAPL Home Page: SIGAPL is the ACM's special interest group devoted to APL.
Association francophone pour la promotion du langage APL: The French Association for the promotion of APL
Capital PC User Group (CPCUG) Home Page: Some interesting APL links here, but they have to be found.
FinnAPL Home Page: Great APL site, specially if you speak Finnish. However, there is much in English also, particularly the very famous FinnAPL Idiom Library.
The British APL Association: Contains committee listing, membership details, a current members listing, and contacts.
Vector's APL Product Guide: Index of APL associations.