At least the agreement and resync protocol should have an alternative implementation. Protocol buffers look promising here.

Note: This must not supercede the HTTPS/XML, which should be developed into a fully documented reference implementation. It should be a compatible (but not bug-compatible) alternative falling back to the base case if not supported at both ends.

Edited to add: Maybe the chrome libraries would actually make a good runtime. (As suggested in the linked article. 2015-01-18)

> urn:about:/hoist#seeAlso
1675 title > Chrome Is The New C Runtime