IBM was big on Rexx when OS/2 2.x was released in ~1993.
"IBM also once engaged in a technology transfer with Commodore, licensing Amiga technology for OS/2 2.0 and above, in exchange for the REXX scripting language. This means that OS/2 may have some code that was not written by IBM, which can therefore prevent the OS from being re-announced as open-sourced in the future. On the other hand, IBM donated Object REXX for Windows and OS/2 to the Open Object REXX project maintained by the REXX Language Association on SourceForge."
https://en.wikipedia.org/wiki/Rexx
https://en.wikipedia.org/wiki/OS/2#Petitions_for_open_source