Graceful Degradation
Summary
Graceful degradation, also known as Fault tolerance is a concept of building a web site or application so it provides a good level of user experience in modern browsers.
However, it will degrade gracefully for those using older browsers. The system may not be as pleasant or as pretty, but the basic functionality will work on older systems.
[…] Graceful Degradation is the journey from complexity to simplicity
You start creating your website or web-application with the use of features that are available in the latest generation of modern browsers. Thereafter, have a look on older browsers and systems and start creating fallbacks by using polyfills or other workarounds.
Examples
Definition of Done: Create a videoplayer that is working on IE6 up to IE10.
Cause you trust the approach of GD, you prefer the HTML5 <video> tag over Flash as your entry point. Now your videoplayer works well on IE9 & 10. You need to create a fallback for IE6-8, that does not support HTML5Video. You’ll now create another instance of your player based on Flash, which is a graceful replacement of your HTML5 player.
<video>
<object id="flash_fallback_1" type="application/x-shockwave-flash" data="player.swf">
<param name="movie" value="video.mp4" />
</object>
</video>