It's not in a workhorse languages category yet, but in a hobby languages, alongside Perl 6. I'm interested in Parse dialect, seems very powerful. Wasn't a user of Rebol previously, but I like that Red mostly reimplements it, without straying to the sides.
And yeah, Parse is very interesting. I would like to do something similar in Spry but perhaps borrowing more from PetitParser (a very nice parser combinator library in Smalltalk from Lukas Renggli)