jKit
A very easy to use, cross platform, jQuery based UI toolkit, that’s still small in size, has the features you need, and doesn’t get in your way of doing things!
17 Alternatives To jKit
Auth0
Auth0 is a program for people to get authentication and authorization services for their own business use.
Bootstrap
Simple and flexible HTML, CSS, and JS for popular UI components and interactions
DevExtreme
HTML5 Widgets & SPA Framework for Desktop and Mobile
Ext JS
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Foundation
The most advanced responsive front-end framework in the world
Gijgo
Gijgo is a set of free open source javascript widgets distributed under MIT License.
GroundworkCSS
Responsive HTML5, CSS and JavaScript Framework
Metro UI CSS
Metro UI CSS a set of styles to create a site with an interface similar to Windows 8.
Ninja UI
Ninja User Interface, the jQuery plugin for lethal interaction.
PhoneGap
Easily create apps using the web technologies you know and love: HTML, CSS, and JavaScript.
Purecss
A set of small, responsive CSS modules that you can use in every web project.
React Native
A framework for building native apps with React
Semantic UI
A UI Component library implemented using a set of specifications designed around natural language
UIKit
A lightweight and modular front-end framework for developing fast and powerful web interfaces
Webix UI
An enterprise JavaScript Library for cross-platform app development with HTML5 JavaScript widgets and easy integration with most popular JavaScript Frameworks.
jQuery
The Write Less, Do More, JavaScript Library.
w2ui
W2UI is a small JavaScript UI library with a complete set of widgets: layout, grid, sidebar, toolbar, tabs, fields, popup, utilities.