Re: multimple domain authentication

user@domain as the userid is already available as an option (i believe
sources' auth database was intended that way originally).  for a
similar idea you may want to look at kerberos realms, where principals
(users) authenticate as:

	user.instance@realm

authentication across realms is possible, but i haven't looked in
depth.
	
	http://publib.boulder.ibm.com/tividd/td/framework/GC32-0803-00/en_US/HTML/plan20.htm

in plan9's case we don't need the .instance (private namespaces take
care of that).

integrating this scheme in fossil may not be the right way to go for
several reasons (off the top of my head):

	- not everybody is using fossil

	- once you add it to fossil you take away the choice of those,
	who don't want to use it

	- it's about accessing resources, not storing files

the last one is possibly the most important -- think of the grid as a
set of service sites and individuals offer for others.  connecting
them seamlessly together is the task of middleware toolkits such as
globus, (or in plan9's case a task for the OS, which is the right way
:).  in that sense an authentication scheme must be general enough to
cover all possible services.  perhaps instead of hacking fossil it's
better to write a dedicated 'grid storage service' (even with fossil
as a backend) where you can implement any scheme you want.

on the other hand, perhaps i'm wrong and letting fossil store files
owned by users not in /adm/users is the right way to go (does fossil
allow that already?  is this a non-issue?)

andrey