While researching for frontend JavaScript frameworks, you'll realize that there are four main open-source contenders: AngularJS, Backbone (http://backbonejs.org/), Ember (http://emberjs.com/), and, the latest kid on the block, React from Facebook (http://facebook.github.io/react/).
Sure, there is jQuery, but it is a library used mainly for DOM manipulations, event handling, and Ajax communication. Similarly, Knockout (http://knockoutjs.com/) is a small framework/library that provides data binding, which greatly simplifies dynamic JavaScript UIs with the MVVM pattern. Likewise, React only caters to the View layer (V in MVC) and isn't a full MVC framework.
However, for a large-scale, database-backed web application, you'll need more than what libraries such as jQuery or Knockout provide. I have no experience with Backbone, Ember, or React, so here are a few links that will help you compare them:
Angular Backbone or Ember: Which is best for your Build? (https://www.codeschool.com/blog/2014/05/15/angular-backbone-or-ember-which-is-best-for-your/)
Angular Backbone Ember: The best JavaScript framework for you (http://readwrite.com/2014/02/06/angular-backbone-ember-best-javascript-framework-for-you)
Backbone and Angular: Demystifying the myths (http://blog.nebithi.com/backbone-and-angular-demystifying-the-myths/)