Joshfire is an Open Source Framework for developing Aplication that can work in cross devices. It helps you develop one unique application using only standards like HTML5 and JavaScript to make it automatically compatible with mobiles, tablets, TVs, and even connected objects.
CSS framework is a pre-prepared library that is meant to allow for easier, more standards-compliant styling of a webpage using the Cascading Style Sheets language (wikipedia).
Popcorn.js is an event framework for HTML5
Ramaze is a simple, light and modular open-source web application framework written in Ruby.
jFormer is a form framework written on top of jQuery that allows you to quickly generate beautiful, standards compliant forms. Leveraging the latest techniques in web design. jFormer helps you create web forms that can validate client-side, server-side and process without changing pages (using AJAX).
Anemone is a Ruby library that makes it quick and painless to write programs that spider a website.
Easy is CSS/HTML/JavaScript framework designed for building layouts. It includes built-in (jQuery powered) interactive functions
CSS3 buttons is a simple framework to create good-looking GitHub style button links.
Zepto.js is a minimalist JavaScript framework for mobile WebKit browsers, with a jQuery-compatible syntax
Zend Framework (ZF) is an open source, object-oriented web application framework implemented in PHP 5 and licensed under the New BSD License
5 Useful JS Framework Plugin for Image Cropping
Centage is a CSS framework that focuses on creating simple to advanced fluid grid layouts easily, developed by Jussi Jokinen
RailsWizard is a free and open source web application that helps you rapidly customize and build Rails application templates.
Ruby On Rails is an open source Web framework that help you to create web applications more easier, faster & write beautiful code by favoring convention over configuration. Here is 3 Free Open Source E-Commerce for Ruby on Rails
jo is a Open source lightweight JavaScript framework and A Pretty UI Widget Framework designed for HTML5 apps capable browsers and devices.