Using the Underscore module with Node.js
As of today (April 30, 2012) you can use Underscore as usual on your Node.js code. Previous comments are right pointing that REPL interface (Node's command line mode) uses the "_" to hold the last result BUT on you are free to use it on your code files and it will work without a problem by doing the standard:
var _ = require('underscore');
The Node REPL uses the underscore variable to hold the result of the last operation, so it conflicts with the Underscore library's use of the same variable. Try something like this:
Admin-MacBook-Pro:test admin$ node
> _und = require("./underscore-min")
{ [Function]
_: [Circular],
VERSION: '1.1.4',
forEach: [Function],
each: [Function],
map: [Function],
inject: [Function],
(...more functions...)
templateSettings: { evaluate: /<%([\s\S]+?)%>/g, interpolate: /<%=([\s\S]+?)%>/g },
template: [Function] }
> _und.max([1,2,3])
3
> _und.max([4,5,6])
6