In addition to open specifications, as the parent pointed out, they also have open source reference implementations. At least in the cast of SPDY, support has already landed in Firefox. Characterizing this as equivalent to ActiveX shows an ignorance of either the original browser wars or Google's modus operandus these days.
WebRTC is a real standards-track technology. If you look at the draft you linked, none of the four editors even work for Google.
In the other cases cited - good luck making an independent interoperable implementation just from Google's "spec". The same would go for WebM and Dart.
Uh, the SPDY spec is excellent (and is IETF standards-track). The WebM "spec" might be something of a joke, but the fastest decoder right now is a third-party, independent implementation.
NaCl and Pepper are well documented (NaCl extremely so), it's just that other browser vendors (namely Mozilla) don't like Pepper's chrome-centric design and don't agree that NaCl is a good choice for the web. Dart is still being designed last I heard, but it's in a pretty similar spot; just because no one else will touch it doesn't mean there's not a decent spec for what is finished.
Dart: http://www.dartlang.org/docs/spec/ SPDY: http://dev.chromium.org/spdy/spdy-protocol WebRTC: http://dev.w3.org/2011/webrtc/editor/webrtc.html NaCL: https://developers.google.com/native-client/reference/pepper... (C API definition)
In addition to open specifications, as the parent pointed out, they also have open source reference implementations. At least in the cast of SPDY, support has already landed in Firefox. Characterizing this as equivalent to ActiveX shows an ignorance of either the original browser wars or Google's modus operandus these days.