If it is XML-esque, then it is obviously plaintext and as such is infinitely easier than binary. As with anything else, your first place to start would be not to actually ask the question of someone else and go about learning on your own. Google is an infinite resource of information and likely the answer resides there long before you ever had to ask the question here.
First step in learning this material is being self-motivated. There is absolutely no other way.
VLX (Visual LISP executable). Similar to the LSP and FAS type of files, a VLX can load and run a Visual LISP program
As AutoCAD is concerned,a VLX is a stand-alone program which means it's completely self-contained.(not divided into multiple files,but the functions/variables/constants/others are inside the file itself)
Though it's tough to be certain from a file extension and a vague discription, I suspect gnukish is correct, namely Visual LISP.
All LISP variant languages are esoteric and powerful and have quite a vast number of possible application delivery models. From your description of it being similar to xml, most likely with parenthesis () rather than angle brackets <>, you will need to do nothing in the way of reverse engineering since are actually looking at the source code.
;-)
JCR
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