content, format, ctype, or xtype ?

[Douglas Tody]

On Fri, 15 May 2009, Alberto Micol wrote:
> In the end Users shall be able to write their own tools!
> And in whatever language they want.
>
> This is the real uptake I'm interested in. User-built tools will be the real 
> demonstration that the IVOA has done the right thing.

I very much agree with this, although we are perhaps dangerously
straying off into design philosophy again.  In designing our
science oriented protocols (DAL for example), we need to balance
two key use cases: direct use of the protocols by the end user
astronomer/programmer/scripter, and use internally for interoperability
within the big projects, e.g., for portal applications or data center
software.  Both are important and are needed, and we really do not
want to split the VO down the middle and separate these two as some
might suggest.  It is possible to support both use cases, but takes
some care.  Much of the controversy within VO circles is due to this
conflict, with some wanting to give only the final super-duper portal
applications to users, and others (myself for one) trying to address
both use cases.

This is an age old issue affecting essentially all astronomy
science software which astronomers use directly for their research.
Ultimately if a research environment is successful much of the
applications functionality will have to come from the user community.

 	- Doug