[Opensim-dev] The essence of "grid"

[Diva Canto]

OK, I think I'm coming close to having the sharp definitions that I 
think are necessary. They're slight variations of Melanie's, because 
Melanie's are still coercing OSGrid-like grids to become something that 
they aren't.

- "Simulator trust domain": a set of simulators that trust each other, 
operated by one single authority

- "Grid": a set of simulators that share resources. Resources include: 
assets, user accounts, and assorted services like lookup services, 
forums, etc. [And this is the thing] A Grid includes one *or more* 
simulator trust domains.

- "Hypergrid": the interconnection of grids.

In most cases (I would expect) a grid contains exactly 1 trust domain. 
But in some cases, it may contain more. If you think about it, the 
Linden Lab grid is a "grid" according to the above definition, and so is 
OSGrid. The mechanisms by which grid operators establish sim trust 
domains are entirely up to the grid operators. They may apply formal 
TOSs or they may put the grid login password on the web. They may issue 
formal trust certificates (one or more sets) or they may not do such a 
thing.


For the purposes of security, it's clear that the client can't talk 
directly to a central grid-wide server, but it has to do it with the 
specific simulators, which then can redirect to their authorities.