Well, I concur; back in the days, I have created quite a few websites with business logic in RXML.
I'd think that both RXML and its Javascript based successor Remixml are both Turing complete and can be used as generic programming languages (within reason). Which is not to say that creating complicated applications in those languages is a good idea.
> anyone who learned programming could see that html/xml/rxml was not a programming language but sophisticated markup.
Leaving aside the "pike" tag, I guess I agree... my original statement was based on the path dependence of having written my first ever production application "in" RXML. ;)