The WAMP project (http://wamp.ws) seems to pursue the same goals than DDP, namely Remote Procedure Calls + Publish & Subscribe. It has a reasonably active community, and is doing some good efforts on specification and implementations.
I wonder if this project could be useful to the meteor ecosystem, either to improve DDP, or even to implement livedata on top of WAMP.
For comparison, here are the relevant links about DDP:
We might be interested in quite a few WAMP features: routers (eg to filter the data traffic — see DoS hardening/rate limiting on the meteor roadmap), more transport protocols supported (including raw sockets — great for the server micro-services communications), and maybe the build-in authentication. I also need to have a closer look at WAMP to verify if there is something about namespacing.
Any thought on WAMP vs DDP?