From a blog posting at status.net on distributed networks of the "social web" - very interesting as it looks like someone has taken a pragmatic view and actually reused some of the existing simple protocols :
Luckily for us, there have been a number of advances in the distributed social Web in the last two years. In Fall of 2009, we started re-designing OMB. We abandoned any attempt at backwards compatibility, so we were really able to come up with a system built of shiny new components that make more sense.
These components are:
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