There's a larger point in the discussion about plaform-specific clients, which is the distinction between a protocol specification and an implementation.
As I look at the ring.cx site, it talks about the implementation. It does not clearly give a oprotocol spec (something like you'd find in IETF), so that someone could write an independent interoperable implementation. Successful protocols are either proprietary walled gardens or have multiple independent implementations. SIP and ZRTP, for example, are the multiple implementation type. If I'm following correctly, ring is opendht for discovery (which would then have to be examined for protocol vs defined by a singleton implementation), something sip-like for bringing up a session with the peer once you find it, probably some kind of STUN/TURN to deal with NAT, and something RTP/ZRTP-ish to transport the bits.
