RE: Question

[Michael Fitzgerald <mike@wyeast.net>]

Sam,

Yes, they are both languages that validate XML documents using XML syntax.
Further, while I do not speak for the RELAX NG TC, I offer just a few
observations.

I compare XML Schema to a stretch limousine with a hot tub and bullet proof
glass while I compare RELAX NG to a classic, rag top sports car. Some are
perhaps less generous about XML Schema than I, and I admit my comparison may
be less accurate and informed than theirs.

IMHO, RELAX NG:

- has a simpler syntax than XML Schema (compare an XML Schema element and
complexType definition [http://www.w3.org/TR/xmlschema-0/] to RELAX NG's far
simpler element definition
[http://www.oasis-open.org/committees/relax-ng/tutorial-20010810.html])

- is more intuitive and easier to learn than XML Schema because it's syntax
is simpler

- is modular thus allowing implementations that are simpler yet conforming,
based on implementer's choice

- is more soundly based on time-tested data models from good, old computer
science [http://www.cobase.cs.ucla.edu/tech-docs/dongwon/mura0619.pdf]

- easily accepts elements from foreign namespaces, making it more flexible
and adaptable to varied needs than XML Schema

- accepts, per implementation, datatype libraries from foreign namespaces,
such as XML Schema Part 2 [http://www.w3.org/tr/xmlschema-2/] or any other
datatype library an implementer may choose or create. In fact, RELAX NG does
not require implementer's datatypes beyond the built-in types string and
token.

- is easy to believe in because it is based largely on the earlier works of
James Clark (TREX) and Murata Makoto (Relax), two  smart, nice guys who were
on the orginal W3C XML WG (James as technical lead) and have sacrificed
their egos for the greater good (no patronizing intended)

- is downright fun

If anyone would like to improve on or beat up on this comparison, by all
means, let's hear from you.

Mike
=====
Wy'east Communications     http://www.wyeast.net     mailto:mike@wyeast.net

Samuel Cheung wrote:

>I am new to RELAX NG. Would someone please tell me what is the main
>difference between RELAX NG and XML Schema? They are both XML based
>schema for validating XML documents. Am I correct?
>
>Thanks,
>
>Sam