Old browsers are a headache for websites: to develop for, to test, you name it, they’re nothing but bad news.
Thankfully modern browsers like Google Chrome, Apple Safari & Mozilla Firefox are not only more open standards compliant, but are generally automatically updated so there’s going to be a lot less legacy versions in the wild.
There’s two techniques I am familiar with to cater for older browsers: graceful degradation and progressive enhancement. Essentially these achieve the same outcome, sites that still work on older browsers, but are different approaches to the same problem.
Graceful degradation is building a site that is optimized for modern browsers, but then adding functionality to gracefully degrade (but still function) when accessed via an older browser.
Progressive enhancement is building a simple site that functions then adding enhancements that work on modern browser technology when it’s available.
Whilst these achieve similar outcomes, I believe we’ve got to a tipping point where a lot of people use non-Microsoft non-legacy browsers so I believe graceful degradation is a better bet in these times.
At work today, we noticed a problem where a Google font wasn’t loading on a dev machine, and our site rendered in Comic Sans (the font we all love to hate), which immediately gave me a great idea: disgraceful degradation: displaying the content of our site in Comic Sans if you’re an IE8 or below user. That should make them upgrade.