This sort of thing has been cropping up in distributed systems quite a bit recently, in the form of CRDTs: commutative replicated data-types. Essentially data structures whose operations commute. This offers a lot of powerful guarantees when it comes to dealing with consistency in a distributed system.

They're an interesting concept, and I'd highly recommend reading more about them.

The original paper: http://highscalability.com/blog/2010/12/23/paper-crdts-consi...

Their use in League of Legends: http://highscalability.com/blog/2014/10/13/how-league-of-leg...

How Riak uses them: http://aphyr.com/posts/285-call-me-maybe-riak

Occam were heavy on this. In Occam you explicitly stated which parts of your program were sequential and which were parallel (i.e. commutative), sequentialism not assumed. Sadly, Occam is a dead language now; it was too far ahead of its time.

The video presentation of this session is available by clicking through the ToC, or Source Materials http://dl.acm.org/citation.cfm?doid=2517349.2522712