Is PubSubHubbub Alive?

I have some web pages that are polled regularly by consumers to check if there is something new on them.

As you may know polling is not exactly the best solution, so I want to change that to some kind of push.

I stumbled over PusSubHubBub ( aka PUSH ) that look fine for my use case. But I don't find many recent references to it ( The protocol ( version 0.4 ) is a draft dated June 20, 2013 ).

Is this protocol still in use ? Was it replaced / overthrown by something else ?

For those of you with sdome experience with that kind of problems, would you recommend it or something else ?