Raphaël JavaScript Library - MIT License

Raphaël is a small JavaScript library that should simplify your work with vector graphics on the web. If you want to create your own specific chart or image crop and rotate widget, for example, you can achieve it simply and easily with this library.

Raphaël uses the SVG W3C Recommendation and VML as a base for creating graphics. This means every graphical object you create is also a DOM object, so you can attach JavaScript event handlers or modify them later. Raphaël’s goal is to provide an adapter that will make drawing vector art compatible cross-browser and easy.

Raphaël currently supports Firefox 3.0+, Safari 3.0+, Opera 9.5+ and Internet Explorer 6.0+.

http://raphaeljs.com/

What can a JavaScript do?

* JavaScript gives HTML designers a programming tool - HTML authors are normally not programmers, but JavaScript is a scripting language with a very simple syntax! Almost anyone can put small "snippets" of code into their HTML pages

* JavaScript can put dynamic text into an HTML page - A JavaScript statement like this: document.write("" + name + "") can write a variable text into an HTML page

* JavaScript can react to events - A JavaScript can be set to execute when something happens, like when a page has finished loading or when a user clicks on an HTML element

* JavaScript can read and write HTML elements - A JavaScript can read and change the content of an HTML element

* JavaScript can be used to validate data - A JavaScript can be used to validate form data before it is submitted to a server. This saves the server from extra processing

* JavaScript can be used to detect the visitor's browser - A JavaScript can be used to detect the visitor's browser, and - depending on the browser - load another page specifically designed for that browser

* JavaScript can be used to create cookies - A JavaScript can be used to store and retrieve information on the visitor's computer


Source: http://www.w3schools.com/js/js_intro.asp