In the meantime, the SAS programming language promoted Lua as an alternative to its legacy macro language (search for "sas proc lua"). I wondered which version of Lua might be used under the hood and issued a quick
proc lua; submit; print( _VERSION ) endsubmit;
To my surprise, the out was
tkLua 5.2
I'm not sure what this tkLua is. It may have been a Lua with Tk bindings, but it's hard to find some up to date information. In addition, "Tk" makes no sense in this context.