I’ve started a repository on BitBucket (my favorite repository site…’cause I don’t like git, sorry github) that has, as of right now, two Notepad++ UDL XML files. Notepad++ had a total overhaul on the UDL back in September of 2012. This made it so that UDL was actually useful. With that in mind, I took advantage of the new system to make a UDL for EBNF and Monkey. EBNF works very well and the Monkey one works fairly well. It has only a minor glitch with the multiline comments, in that it just won’t highlight it, but it’s not a huge deal. I suppose it also has issues with identifiers that have numbers at the end because of something to do with the number detection that’s screwed up. Until a newer version of UDL addresses that, for the most part you will never notice.
You can pick it up from here: https://bitbucket.org/Goodlookinguy/notepad-udl-collection/overview