Q:

Nowjs: [RangeError: Maximum call stack size exceeded]

When I start the server on port 8080 it doesn't give me an error, but when I am trying to browse the http://localhost:8080/nowjs/now.js the server raises an error:
[RangeError: Maximum call stack size exceeded]
undefined
I tried the same with socket.io and it worked fine.

A:

Hmm, if now.js uses date.js, maybe your issue lies here. What the link says is that date.js tries to set a toString to Date prototype, but when toString is already defined, you get the circular reference mentioned in the other answers.
Basically, they say that in date.js, you change
Date.prototype._toString=Date.prototype.toString

to
if(Date.prototype._toString==undefined) {Date.prototype._toString=Date.prototype.toString;}

I hope it will help someone. It helped me.

A:

Aadit, have you read the following:
Maximum Call Stack Size Exceeded During a setTimeout Call
Uncaught RangeError: Maximum call stack size exceeded, JavaScript
So, as you may see the problem seems to be arising because of the an improper use of stack sizes. If you haven't already you may read a bit more about this problem in detail here along with a possible solution:
Maximum call stack size exceeded error
I don't think it has anything to do with the port, more with the methods/functions in the manner you're interacting/using the stack.
Then again, I may be wrong. ;D

A:

I've had two problems with now.js that produce this error message. Hopefully one of them will help you.
Circular References
You cannot include any circular references in objects passed into now, or it's extend method will barf. There were some optimizations and workarounds for this and it's now  listed as an closed issue, but I have run into it.
initialize() only once
Second, you may not call require('now').initialize(...) twice or the two instances have a little intellectual conversation and race each other right out of the stack.
What I did instead was to create everyone in app.js and pass it into all my require(...) methods that need to reference the now "pocket".
In /app.js:
var conf = {
    everyone: require('now').initialize(app)
    port: 3000,
    // etc...
};

require('./routes')(conf)
// etc...

In routes/index.js:
module.exports = function(conf) {
   var everyone = conf.everyone;

   return {
       send: function() {
           everyone.now.clientFxn(...);
       }
   }
}

