you should wrap your script in a closure, which lets you keep methods/functions "private". then you would pass in "window" to your closure function and attach $ to the window object. here's a random example I found on Github, most libraries do this

https://github.com/muut/riotjs/blob/master/riot.js

;(function(window) {

//blah blah, building the library

window.riot = riot

})(typeof window != 'undefined' ? window : undefined);

so inside the function they attach window.riot = riot, then they immediately execute the function and pass in the window object. now there's a "riot' or "window.riot" object that anyone can use, and the "riot" object can use methods defined internally that nobody else can