@zeenix@pid_eins Before world-conquest IMO we still need a spec of the protocol. It doesn't need to be very detailed (like D-Bus) but still something implementers can use. We'll want bindings for many languages than currently supported. Even many C people would like a gobject-based API and it'd be hard for people to be motivated to write such from-scratch libraries, if they don't have a spec to follow.
So if you really want to push for varlink, I'd suggest creating and publishing that.
@zeenix @pid_eins basing certification on whether an implementation produces messages that can be consumed by other implementations and consume messages they produce kind of makes it look like there isn't any distinction.
As an example, {"method": "foo", "method": "bar"} is valid JSON, and will likely be accepted by most (all?) implementations. Most will probably also decide that you meant to call the "bar" method. It probably shouldn't be considered a valid message though.