Here are 14 amazing web UI frameworks that will help you speed up and simplify front-end web development .

UI KIT

A lightweight and modular front-end framework for developing fast and powerful web interfaces.

Polymer

Polymer is a new type of library for the web, built on top of Web Components, and designed to leverage the evolving web platform on modern browsers.

Rock Hammer

A curated project library for Hammer For Mac. Rock Hammer contains baseline typography, plus styling for common HTML elements including images, forms and tables, as well as navigation, responsive modules and widgets.

Ink

Ink is a set of tools for quick development of web interfaces. It offers a fluid and responsive grid, common interface elements, interactive components, a design-first approach with ease of use and simplicity at its core. Start integrating Ink in your projects and remove the hassle of building the basics, staying free to focus on what’s important.

BootMetro

Simple and complete web UI framework to create web apps with Windows 8 Metro user interface.

iUI

iUI is a framework consisting of a JavaScript library, CSS, and images for developing advanced mobile webapps for smartphones & mobile devices.

Vaadin

Vaadin is a Java framework for building modern web applications that look great, perform well and make you and your users happy.

Web Elements

This is a high quality set of over 80 Web Elements. It features clean code, beautiful design, and elegant jQuery effects. Whether your a web developer looking to save time on your web projects, or a business owner looking to spice up your website, this Elements Set will absolutely deliver the results you’re after.

Bootstrap

Bootstrap is incredibly responsive, with a refreshingly clean design and it has some awesome features! Bootstrap is a simple, clean and professional template suitable for any business or portfolio. Bootstrap is created by using the latest HTML5 and CSS3 techniques. With a responsive design it works great with any device (desktops, tablets, smartphones, etc).

SproutCore

SproutCore is a framework for building blazing-fast, desktop-like applications in the web browser using only native HTML5 features. With SproutCore, you can build rich, interactive applications in the web in less code than most simple web pages require today.

Uki

Uki is a fast and simple JavaScript user interface toolkit for desktop-like web applications. It comes with a rich view-component library ranging from Slider to List and SplitPane.

Wijmo

Wijmo is a complete kit of over 40 UI widgets with everything from interactive menus to rich charts.

YUI

YUI is a free, open source JavaScript and CSS library for building richly interactive web applications.

Kendo UI

Kendo UI is JQuery-based framework for rich UI, build HTML5 apps that look native on any device, build desktop and mobile applications for any browser.