When I first started speaking to audiences on the NFJS tour a few years back, I presented on RELAX NG — the world’s only comprehensive and sane XML schema language. At the time, I spoke to audiences that nearly universally had never heard of it and some subset of whom either quietly or rather vocally considered me stupid, crazed, or simply naive for considering it a viable option.
I admit, back at the height of XML Schema‘s popularity, I was perhaps tilting a bit at the windmills. Don Box told me in a group setting essentially, “If I could wave a magic wand and make us all use RELAX NG, I would, but XML Schema won. Get over it.”
And now, it appears the tide is turning. I couldn’t be happier. Though I want back all the wasted time and effort XML Schema foisted upon us.
(My old RELAX NG slidedeck is here; I think this dates back to 2004).
Ben Galbraith 
The tide is turning because the main proponent of Relax NG is saying so? (no offense to Tim, he’s a great technician and I love his blog)
Sorry, but as little a fan I am of XML schemas, they are here to stay and Relax NG is completely unknown beyond academia.
Don was right: schemas have won, get over it and help the world deal with them. It will be a much more productive use of your energy…
x: Tim is far from the main proponent of RELAX NG, and I was more referring to elharo’s blog than Tim’s.
I’ll take any momentum I can get towards RELAX, though I used the question mark in the blog entry’s title to show that I too am somewhat skeptical.
You can even use a sehmca initially if you want, if that is really your lingua franca, but your real problem is getting the other party to *tell you* what the format is! This problem you are describing has nothing to with validation vs no validation.