“A Glimpse of Icon”, Linux Gazette, April 1998, is available at http://www.linuxgazette.com/issue27/jeffery.html. This article incudes links to RPMs for the system, the Icon Program library and more.
Source code, executables and documentation for Icon are available from the University of Arizona, where it was invented by Ralph Griswold and a cast of dozens. The Icon Project web site is at http://www.cs.arizona.edu/icon/. There is also a newsgroup on Usenet: comp.lang.icon.
The definitive book about the language is The Icon Programming Language, by Ralph and Madge Griswold, Peer-to-Peer Communications, 1997 (ISBN 1-57398-001-3). Users who want to do graphics will also want Graphics Programming in Icon, by Ralph Griswold, Clinton Jeffery and Gregg Townsend, Peer-to-Peer Communications, 1998 (ISBN 1-57398-009-9).
