require('socket.io')(server)

[MSergW]

system: ubuntu server 12.04 x86_64
express@3.1.0 node_modules/express
socket.io@0.9.13 node_modules/socket.io

var app = require('express')();
var server = require('http').Server(app);
var io = require('socket.io')(server); // line 41

Error:
/chat/server.js:41
var io = require('socket.io')(server);
^
TypeError: object is not a function
at Object. (/chat/server.js:41:30)
at Module._compile (module.js:449:26)
at Object.Module._extensions..js (module.js:467:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.runMain (module.js:492:10)
at process.startup.processNextTick.process._tickCallback (node.js:244:9)

But if change on: var io = require('socket.io').listen(server); - it's work

[3rd-Eden]

Yes, because that's right way to call the function. Please read the documentation on http://socket.io

[3rd-Eden]

Also the readme states:

This Readme corresponds to the upcoming 1.0 release. Please refer to http://socket.io for the current 0.9.x documentation.

[iampatgrady]

wow, way to be a dick.

[rauchg]

@iampatgrady it's my bad for not being clear and having a broken master. I'm looking to update this asap.

[iampatgrady]

was referencing the comment above, "Yes, because that's right way to call the function". Just saying, pretty unhelpful response considering the github documentation is the first Google search result for this error :-/

[bladepan]

I encountered a similar problem and solved it. What happened to me is the version of xmlhttprequest which socket.io depends on is not the same with the one sits in my node_module folder. These two xmlhttprequest packages both have the version number 1.5.0, that is why npm decides not to download an extra copy for socket.io, and screws everything. Just delete the dependency on xmlhttprequest would solve the whole thing, the version socket.io uses keeps backwards compatibility. It is so annoying that they add new things in the export and not change the version number.