Produce valid HTML 5, stop efforts getting the MoinMoin output HTML4 or XHTML valid.
Right now, MoinMoin doesnt even output valid HTML 4 sometimes. As XHTML is already much harder to achieve I would vote for stopping all efforts in this and put all energy in HTML5 which is now coming.
The HTML 5 specification learned from the last years and the new requirements needed in the world wide web, and additional to a few new elements it is much easier constructed, just look at the new doctype:
<!DOCTYPE html>
Additionally you didn't even need a closing tag if there is nothing more in the line of the document, for example:
<dialog> <dt> Now then, some cheese please, my good man. <dd> (lustily) Certainly, sir. What would you like? <dt> Well, eh, how about a little red Leicester. <dd> I'm, a-fraid we're fresh out of red Leicester, sir. </dialog>
I think especially that point could make parsing web pages sometimes really easy.
As HTML 5 is now for sure coming, I would put all efforts in this version, as it will stay for the next forseeable future, and become the new standard. Most features are stable and will be implemented as they are written down yet. For the differences look here: http://www.w3.org/TR/html5-diff/
Comments
The main point is, till all visitors / users will updating their browser to support fully html5 code, it will take some years. For example: on our commercial sites we still have between 10-15% IE6 users in 2010, this mean 9 years. Sure the switch in the future well be shorter, but you still have to consider that it takes a few years. Another point is, XTHML is kind of backward compatible - html5 is not (because it contains also new tags, etcetera). Also if you use now XHTML future browser will also support this syntax for sure and in longer future you still can transform / output the stuff to html5 (actual you just need to rewrite the moinmoin output stuff / parser). So no hurry for the next two or three years to jump "headless" into a new "soap"... just my 5cnets -- MarcelHäfner 2010-01-19 22:17:37