Future of NeXus

[Ray Osborn]

The SNS is extremely interested in adopting NeXus as their standard format,
but want us to assure them that we do intend to migrate to HDF5.  The reason
is that they anticipate needing larger files than HDF4 permits (2GB, I
think) and think the HDF5 performance will more closely meet their needs.  I
think that having the SNS endorsement is extremely important to us, partly
for the symbolic importance and partly because, as times goes on, they will
start providing meaningful resources for future software development.  They
might even help with the HDF4 to HDF5 migration.

We have, of course, discussed this before, and I think the general consensus
then was that we would definitely migrate at some stage, but that we were
holding off until there was greater third-party support.  This is the
message that I plan to give to them as our official position.  If anyone has
any complaints about this policy, please send messages to this list as soon
as possible.  I would like to give them this assurance later this week.

While accepting that, I don't think that we are going to be able to hold off
the migration for too long, since it will only make it more difficult to
make the transition.  The issue of third-party tools won't be so serious
once our own tools become better developed.  For example, do we need IDL
support for HDF5, or can we implement Mark's IDL interface as external
procedures?  On the other hand, there isn't even a VMS version of the HDF5
library yet, so I'm not saying we make the transition tomorrow (actually, we
might have to do that one ourselves - any volunteers).

I hope that those of you who attended thought that NeXus was
well-represented at NOBUGS.  I've read the abstracts, and would like to
update the web pages with some of the new stuff you presented e.g. on the
XML proposal, web servers at PSI, and the NIST open source effort.  If the
talks or posters are in electronic form, please send them to me, if you have
no objection.  Also, if there is any software to download, let me know what
URL to point to.  I think that it is important that we maintain the web
pages as a centralized source of information on NeXus, or we will have
problems with fragmentation of the standard + some of the developments seem
very exciting, so let's publicize it.

Regards,
Ray
-- 
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