The Rexx Language Association is an independent, non-profit organization dedicated to promoting the use and understanding of the Rexx programming language. RexxLA manages several open source implementations of the Rexx language.The 2012 yearly RexxLA symposium was held 13 May 2012 to 16 May 2012, in the Raleigh-Durham Area, North Carolina, US. It was the 23rd International Rexx Language Symposium. This Proceedings publication contains interesting and informative presentations on the Rexx Programming language, in all its variants.The RexxLA website can be found at https://www.rexxla.org