CSS3 Playground is a client side web application for trying out different css styles. Use this web application to experiment and learn about new css3 capabilities. The styles applied when changing the different settings should follow the principles of progressive enhancements and will work in all browsers that support the setting. Just change the settings and see how the rectangular box changes according to your changes. Run the site in different browser to see what the differences are. This

JSONmate is a JSON editor component for you web apps/pages. You can beautifier/uglifier your JSON code and edit it directly in a tree view editor, the corresponding JSON code will be generated automatically for you to use.  

JointJS is a modern HTML 5 JavaScript library for visualization and interaction with diagrams and graphs. It can be used to create either static diagrams or, and more importantly, fully interactive diagramming tools and application builders. JointJS makes it easy to create visual languages & tools of various kinds.   The event-driven nature together with MVC architecture of JointJS makes it easy to plug-in any backend application.   JointJS - Features: basic diagram elements (rect, circ

SlickQuiz is a jQuery plugin for creating pretty, dynamic quizzes. There are many options available. You can chnage the number of questions to load from the question set in the JSON object, sort questions and answers randomly, prevent submitting a question with no answers and so on.  

Font Sizer is a highly configurable, unobtrusive jQuery plugin that allows users to adjust the font size of specific area(s) of text on your website. It's lightweight, easy to configure and adds a nice bit of functionality to your blog, forum or news site.  

Colorbox is a lightweight customizable lightbox plugin for jQuery. It accepts settings from an object of key/value pairs, and can be assigned to any HTML element. Colorbox - Features: Supports photos, grouping, slideshow, ajax, inline, and iframed content. Lightweight: 10KB of JavaScript (less than 5KBs gzipped). Appearance is controlled through CSS so it can be restyled. Can be extended with callbacks & event-hooks without altering the source files. Completely unobtrusive, options are

WordCount.js is a client-side JS and Node.js library that counts bytes, words, lines, chars, and calculates the longest line of a file using the HTML5 File API.  When a file is uploaded using the file input element with the given input selector then the number of bytes, words, lines, chars, and the longest line in the uploaded file are calculated and then callback is called.  

jQuery contextMenu was designed for web applications in need of menus on a possibly large amount of objects. This contextMenu treats the menu as the primary object. That means, that a single menu is defined that can be used by multiple objects. This context menu plugin doesn't need to bind itself to triggering objects. This allows injecting and removing triggers without having to re-initialize or update contextMenu.   This plugin can provide a simple list of clickable commands, or offer an in-

jQuery Grid 'Em is a simple jQuery plugin that allows you to evenly apply horizontal spacing on a list of items across multiple rows on a page.   

Mosaic Flow is a Pinterest like responsive image or HTML grid plugin for jQuery.    Mosaic Flow - Features: Simple and easy to install. Responsive (shows as many columns as needed). Very fast. Only 1.5 KB (minified gzipped). You can use bare <img> tags or arbitrary HTML.