Why APL? - Anonymous essay from 1983 published by ACM SIGAPL, which explains the strengths of the APL approach to algorithm design. - http://www.sigapl.org/whyapl.htm
APL Programming Language - Growing article, with links to many related topics. [Wikipedia] - http://en.wikipedia.org/wiki/APL_programming_language
Hello, World Program - Several variants written in APL. - http://www2.latech.edu/~acm/helloworld/apl.html