Once upon a time, when the Web was young, frontend development was a lawless profession. Designers and developers alike had to navigate a Wild West of browser hacks, proprietary "standards" and a glacial browser update process. "This won't work in IE," we would say forlornly. "If only web standards were more widely supported."
Fast-forward to 2013 and we've come a long way. Browsers now update themselves, and browser vendors work with the W3C to push the web forward. But our work is not done. Different browsers implement different standards in different ways. How are we to know what we can and cannot use?
Meet the noble polyfill.
As we emerge from the gloomy depths of the web's past, the path ahead of us looks bright. New features such as grid layouts, WebGL and native video can be seen on the horizon—and thanks to the magic of polyfills, all of the web's citizens can enjoy them.
Let's work together to end lowest common denominator web development, one feature at a time.
A lightweight polyfill for browsers that don't yet support srcset (non-webkit nightly).Official Website
The HTML5 Shiv enables use of HTML5 sectioning elements in legacy Internet Explorer and provides basic HTML5 styling for Internet Explorer 6-9, Safari 4.x (and iPhone 3.x), and Firefox 3.x.Official Website
A responsive images approach that you can use today that mimics the proposed picture element using spans, for safety sake.Official Website
An update to CSS3MultiColumn by Cédric Savarese to support HTML5 elements.Official Website
A fast & lightweight polyfill for min/max-width CSS3 Media Queries (for IE 6-8, and more).Official Website
Adds grid layout support to IE9+ by changing the CSS without editing any DOM elements.Official Website
PIE makes Internet Explorer 6-9 capable of rendering several of the most useful CSS3 decoration features.Official Website
visibly lets you easily establish whether a page currently being viewed in the browser is visible to the user or has been hidden by them switching to another tab.Official Website
Visibility.js is a wrapper for the Page Visibility API. It eases usage of the API by hiding vendor-specific property prefixes and adding some high-level functions.Official Website
This plugin gives you a very simple API that allows you to execute callbacks when the page’s visibility state changes.Official Website
mOxie is combined name for XHR2 and File API pollyfills extracted from Plupload in order to make it more flexible and give it opportunity for further growth.Official Website
Shims the saveAs method, using saveBlob in IE10, an object URL resource in Chrome or a new tab in FireFox.Official Website
FileSaver.js implements the HTML5 W3C saveAs() FileSaver interface in browsers that do not natively support it.Official Website
Dropfile is a shim which uses Silverlight to recreate the part of the HTML5 FileAPI which lets us drag files into the IE browser and read 'em.Official Website
Silverlight Canvas uccessfully uses Silverlight as a rendering engine to implement HTML 5 <canvas> support in IE6—IE8. It also enables onload=".." attribute support for native canvas renderers for 'this' context object activation.Official Website
fxCanvas is an implementation of the HTML5 Canvas element for Internet Explorer (two-dimensional graphics only).Official Website
Modern browsers like Firefox, Safari, Chrome and Opera support the HTML5 canvas tag to allow 2D command-based drawing. ExplorerCanvas brings the same functionality to Internet Explorer.Official Website