Rex Swain's Home Page:Many articles of interest to new and old APLers, an interesting smattering of information on other languages (REXX, Perl, HTML), and much other information. A site of interest not only to APLers, but to many computer users!
APL White Pages: A directory of many serious APL users all over the globe
Jim Weigang's APL Information: Many articles, programs, definitions, and links.
Oleg's J Page: Various user scripts in J. Links to other J sites.
Présentations AFAPL: Part of the site of a French speaking APLer.
Sam Sirlin's APL Page: Useful APL information and links. Particularly interesting is the APL c compiler project, based on T. Budd's original work.
Timothy A. Budd home page: The creator of Little Smalltalk does APL too.
Yoshi's APL Page: APL and Japanese Language and Japanese Market.