[ClassicFarris]

For Machine <-> Machine we have several that don't use HTTP, such as Thrift, ProtocolBuffers, etc.

For browser to Machine, I'm not sure we need that. The reason is, for example, we can use JSON which is very easily consumable by a machine over HTTP. HTTP provides all of the transport niceties like headers, verbs (which translate fairly well to CRUD), etc. So the combination of a fairly well featured transport layer combined with fairly well machine consumable data document format makes a pretty good protocol.

Which parts can change for the better in specific relationship to a machine-centric API protocol.