Rexx became reality on March 20th, 1979. Why is that day considered Rexx's birthday? According to Mike Cowlishaw, "'twas the day I woke up at 3am with a clear idea of what was needed, and by the end of the day had the initial specification off around the world for comment."
For many years the definitive web site for Rexx information was Mike Cowlishaw's Rexx Page. To ensure that this piece of Rexx history was not lost, in 2005, Mike graciously donated the contents of his web site to RexxLA.
IBM played a major part in the development of Rexx and some of their involvement can be seen in their IBM Rexx announcements.
Information about the REXX Standardization can be found at the Rexx Standard page.