They have been building it for more than a year I think... It's a very complex distributed social platform. We should invite them on Beyong Bitcoin Hangout ans learn something that could benefit Steem.

Social Contracts

Synereo features a battle-tested, robust smart contracting mechanism that does not rely on global consensus.
In a decentralized, distributed network there is a natural and vital tension between the desire for reach and the desire for privacy. Enforceable statements about the intent for how information is to flow provide the means to reconcile and harness this tension into a powerful force for social self organization and self determination. In Synereo, social contracts allow agents to state and enforce information flow policy. Policy statements are made independently and autonomously, yet can be assembled to define and determine the information flow policy of a collective. Policy can be checked for properties such as 'this group learns of an event before that one,' or 'everybody eventually gets notified of an important message.'

Using properties, agents can check to see whether combined information flow policies fit with their aims and goals in order to decide when and how to participate in information/currency exchange with other agents and collectives. Among the many benefits, this allows for just-in-time assembly of services without a global director or global coordinator.