Some other JavaScript frameworks include: MooTools, Backbone, Sammy, Cappuccino, Knockout, JavaScript MVC, Google Web Toolkit, Google Closure, Ember, Batman, and Ext JS.
Some of these frameworks also use the $ symbol as a shorthand (just like jQuery). If you are using two different frameworks that are using the same shorthand symbol, it may cause the script to stop running.
The jQuery team took this issue into consideration and implemented the noConflict() method.
Example
You can also create your own abbreviation. noConflict() returns a reference to jQuery that you can store in a variable for later use. Please look at this example: