Wee

Wee is a front-end framework for developing responsive websites using a mobile-first CSS bootstrap paired with a powerful JavaScript library.
Flat UI Pro

Flat UI Pro is Twitter Bootstrap Design Framework that includes HTML and PSD versions. Flat UI Pro contains a huge number of basic components, themes, icons and glyphs.
Kube Web Framework

Free CSS/JS advanced and flexible framework.
DevExtreme

HTML5 Widgets & SPA Framework for Desktop and Mobile.
Gridlex

Simple. Robust. Responsive. Flexible.
Ractive.js

Ractive.js is different.
Famous Engine

The Famous Engine is a free and open source JavaScript rendering engine.
Element UI

A Desktop UI Library. Element, a Vue 2.0 based component library for developers, designers and product managers.
HTML5 Boilerplate

A rock-solid default for HTML5 awesome.
KnockbackJS

Both Knockout.js and Backbone.js have their strengths and weaknesses, but together they are amazing!