DTDs, W3C Schemas, RELAX NG, Schematron?

Hey all:

DTDs?
W3C Schemas?
RELAX NG?
Schematron?

What - first off - is the *best* route to take from a
developer's stance?  Second, can these technologies
work in conjunction with one another, or must they be
implemented seperately in order to reap the (read any)
desired result(s)?

Also, where has all the buzz surrounding RELAX NG
gone?  It was not too long ago when it seemed to be a
very hot topic.  Finally, does anyone care to share
their opinion(s) on the future of DTDs?



Regards,


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T. A b d u r - R a h i m
W e b  D e v e l o p e r

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creates better living.

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