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 2015 yearly RexxLA symposium was held 29 Mar 2015 to 1 Apr 2015, in Vienna, Austria. It was the 26th 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