This document has a long history. Edward Yung was the original author of Eden, and the language reference manual started life as Appendix B in his 1987 third year project report. It then became Appendix A in his 1989 MSc thesis. Later it was circulated as a printed copy. It was converted to HTML in the early days of the World Wide Web by Mike Joy. In 2005, Ashley Ward placed it in Warwick's SiteBuilder content management system, reworking the document structure to a single level of hierarchy. It still stands as a useful introduction and reference for the Eden language, but is out of date in some parts, particularly with respect to built-in functions. The most up to date information is in a "Quick Reference" guide written by Ashley Ward, available from the Help menu within the EDEN tool and now also included at the end of this document.