Pusher library for Node.js or PHP which can subscribe to channels?

I'am trying to build server-side client for Pusher. Client shoud be able to subscribe to channels and react to events... After getting info from DB etc it shoud send info to another clients (Javascript, Arduino).

Problem is I cant find any server side library which will be able subscribing to Pusher channel and binding to events...

Is something like this already written? Do you have some tips?

here - https://github.com/abhishiv/pusher-server

pusher client for node.js

Not actually related to the Pusher.com but you could take a look at faye for node.js. It's not actually a different service. You will have to host it, and I'm not saying it's better or worst than Pusher.

http://faye.jcoglan.com/

Node specific http://faye.jcoglan.com/node.html

You can create a server in node.js. (Example from the guides)

var http = require('http'),
    faye = require('faye');

var bayeux = new faye.NodeAdapter({mount: '/faye', timeout: 45});
bayeux.listen(8000);

And client at server side node.js in a different server, so you can publish or subscribe to channels. (At the faye server there is a client already attached)

var client = new faye.Client('http://localhost:8000/faye');

And you can also use it in the browser

<script type="text/javascript">
    var client = new Faye.Client('http://localhost:8000/faye');
</script>

Since an answer hasn't been chosen I will answer with what I used in May 2014: Pusher Node.js Client

This library is an open source client that allows Node.js applications to connect to the Pusher webservice. It aims to be fully compatible and up-to-date with Pusher's official JavaScript client. Github.com/dirkbonhomme