JS Framework!

JS(JavaScript) is used to do Client side Validations.

Some of Web Application related JS Frameworks are

AngularJS: AngularJS (commonly referred to as "Angular" or "Angular.js") is an open-source web application framework mainly maintained by Google and by a community of individuals. The AngularJS library works by first reading the HTML page, which has embedded into it additional custom tag attributes. Angular interprets those attributes as directives to bind input or output parts of the page to a model that is represented by standard JavaScript variables. The values of those JavaScript variables can be manually set within the code, or retrieved from static or dynamic JSON resources.

Backbone.js: Backbone.js is a JavaScript framework with a RESTful JSON interface and is based on the model–view–presenter (MVP) application design paradigm. Backbone is known for being lightweight, as its only hard dependency is on one JavaScript library, Underscore.js, plus jQuery for use of the full library. It is designed for developing single-page web applications, and for keeping various parts of web applications (e.g. multiple clients and the server) synchronized. Backbone was created by Jeremy Ashkenas, who is also known for CoffeeScript and Underscore.js

Cappuccino: Cappuccino is an open source application development framework for developing web applications that look and feel like desktop applications on Mac OS X. Cappuccino was developed by University of Southern California graduates Francisco Tolmasky, Tom Robinson and Ross Boucher, who are also the founders of 280 North, Inc. It is primarily targeted towards web applications developers.

Ember.js: Ember.js is an open-source JavaScript application framework, based on the model-view-controller (MVC) pattern. It allows developers to create scalable single-page web applications by incorporating common idioms and best practices into the framework. Ember is used on many popular websites, including Discourse, Groupon, Vine, Live Nation, Nordstrom, and Chipotle. Although primarily considered a framework for the web, it is also possible to build desktop and mobile applications in Ember. The most notable example of an Ember desktop application is Apple Music, a feature of the iTunes desktop application.

Ext.js: Ext JS is a pure JavaScript application framework for building interactive cross platform web applications using techniques such as Ajax, DHTML and DOM scripting. Originally built as an add-on library extension of YUI by Jack Slocum April 15, 2007, Ext JS includes interoperability with jQuery and Prototype. Beginning with version 1.1, Ext JS retains no dependencies on external libraries, instead making their use optional.