[Nexus] Changes to the web site

[Ray Osborn]

1) One of the things most urgently requested at the NeXus'2001 workshop was
a simpler introduction to NeXus itself - more on the lines of a tutorial
rather than the dense explanations of the existing site.  It has only taken
me 16 months to comply.  If you visit the NeXus home page, you will find
that the old introduction has been moved to a "Background" page and been
replaced by a completely new introduction, which attempts to explain what
NeXus is and how it can be used.

I would really welcome some feedback (preferably to this list, since we
should use it more) about whether it does what was asked, and whether more
should be added.  It is very difficult for me to judge.

2) Some of you are aware that I have introduced a new XML metaformat, which
is designed to help in standardizing the instrument definitions.  You will
find a description of this format, as it is now proposed, at
<http://www.neutron.anl.gov/nexus/NeXus_metaformat.html>.  You will also
find colorized versions of some of the group definitions if you follow the
links at <http://www.neutron.anl.gov/nexus/NeXus_contents.html#Glossary>.

The XML metaformat is not a rigorous XML definition, like a DTD or Schema,
but it is more readable and has sufficient rigor to allow such DTDs to be
constructed automatically.  It uses a simple GREP syntax (*,+,?) to define
optional groups and data items.  By adding an $ID$ tag to the introductory
comment tag, we can get a CVS server to add version numbers.  That means
that, for example, we can state that a program can read v1.12 of the TOF
SANS definition (TOFSANS.XML), and allow for future upgrades in a properly
documented way. 

Comments on this as well please.  If they are positive, then the instruments
will be defined by these XML files, rather than the web pages, which were
always a little vague on many details.  I know that others have other ideas
about making these definitions more rigorous, but this is a start.

Regards,  
Ray

P.S. Version 2.0.0 (HDF4+HDF5) is working for Linux and Mac OS X, but we are
waiting for some things to be sorted out in the Windows version before
officially releasing it.  Sorry for the delay.
-- 
Dr Ray Osborn                Tel: +1 (630) 252-9011
Materials Science Division   Fax: +1 (630) 252-7777
Argonne National Laboratory  E-mail: ROsborn at anl.gov
Argonne, IL 60439-4845