XProc is now a Candidate Recommendation

http://www.w3.org/TR/2008/CR-xproc-20081126/

But what is XProc ? What is it for ? Why do I need it ?

What is XProc ?

XProc is language for describing transformation in XML.

Wait a minute ! Isn't there already dozens of technologies around doing exactly this : Java, Perl, SAX, StAX, DOM, XQuery and XSLT ?

Well, indeed ! but XProc is more there to coordinate the transformation using those technologies : defining conditionals, repetitions and modules.

So with XProc you will be able to use XSLT, XQuery and more or less any other language of your choice (by using extensions).