Yes. It's a decent implementation. However, binary data access (particularly DataView which is used by protobufjs) is embarrassingly slow in all browsers at the moment, so JSON (possibly gzipped if you're worried about bandwidth) is much better if you're going to be mainly targetting browsers.
Comments
Anyone tried ProtoBuf.js "Protocol Buffers for JavaScript." on the client side?
https://github.com/dcodeIO/ProtoBuf.js
Yes. It's a decent implementation. However, binary data access (particularly DataView which is used by protobufjs) is embarrassingly slow in all browsers at the moment, so JSON (possibly gzipped if you're worried about bandwidth) is much better if you're going to be mainly targetting browsers.