Roger K.W. Hui, Dyalog Limited, Canada
Morten J. Kromberg, Dyalog Limited, United Kingdom
History of Programming Languages IV (HOPL IV)
APL Since 1978
ACM SIGAPL The Association for Computing Machinery's Special Interest Group for Array Programming Languages has some J material.
Albert Stevens Notes on use of J, and collection of other J related material at UNB Transportation.
BrianSchott's YouTube J screen casts: download and install, an introduction via Labs, browsing locales with cobrowse.ijs, and a simple openGL screen robot. Search for "J Programming Language" for more.
Cliff Reiter's Gallery of Fractals, Chaos and Symmetry at Lafayette College.
Donald B. McIntyre's site includes Mastering J Revisited.
Ewart Shaw's page at University of Warwick has a thorough guide to J.
John Howland's pages at Trinity University, San Antonio.
Keith Smillie's J Page at University of Alberta has several excellent introductory articles, including a statistical package written in J.
Ken Gordon has a review A management perspective of the J programming language among other recommended data warehousing and compression articles, some archived.
Martin Neitzel's Juggler's page at Gaertner Datensysteme GbR.
Mstat is a standalone package for statistical analysis, developed by Norman Drinkwater at the McArdle Laboratory for Cancer Research, University of Wisconsin.
Oleg Kobchenko's J Page has several useful J scripts.
郭平欣 J 字典 及J 語言初步. Ping-Sing Kuo's Chinese translation of the J Introduction and Dictionary and 51-page J Introduction.
Словарь Языка J (archive, PDF). Russian translation of J dictionary. This is a working copy, sublect for discussion and change. Please comment on it here. Periodically (e.g. after J 6.01 is out) it will be assembled into a higher quality releases, made available elsewhere.
Skip Cave's site includes various historical APL/J papers, as well as digital pictures taken at the J2000 conference in Toronto.
LiteratePrograms Examples of J code elaborated in "literate" style.
Rosetta Code Examples of J code for comparison and contrast with other programming languages.
Vector Journal of the British APL Association with many articles on J.
Wikipedia entry J programming language