When Netscape started the Mozilla browser, it made the conscious decision to support W3C standards. As a result, Mozilla is not fully backwards-compatible with Netscape Navigator 4.x and Microsoft Internet Explorer legacy code; for example, Mozilla does not support as I will discuss later. Browsers, like Internet Explorer 4, that were built before the conception of W3C standards inherited many quirks. In this article, I will describe Mozilla’s quirks mode, which provides strong backwards HTML compatibility with Internet Explorer and other legacy browsers.
Testing your sites on different versions of Internet Explorer has always been notoriously difficult mainly due to the fact that Microsoft prevents you from running to different versions of the browser in Windows. Sure there have been solutions to get around this limitation but in my experience, they’ve always caused unexpected results and instability for the operating system or required you to run a VM. Not ideal.
Two related posts about the same problem. The solved mine 🙂
While working on a new site, I started playing around a little more with 8-bit PNG files, comparing them to GIFs. In a few cases the PNG was smaller (it didn’t used to be that way, but perhaps Photoshop CS2 does a better job of compressing PNG files or something), so used it. All was good until I started testing the design in IE, where the colors were all off. Here’s a breakdown of how the same graphic (placed as a CSS background image against a background color equal to its own background color) rendered between the two browsers:
In setting up the new vehicle details page for DDC, I noticed that the background color for the 24-bit PNGs did not match the css background color, but only in IE6.
Searching online, I found this is a known bug with IE that stems from a flawed interpretation of the PNG’s gAMA setting. It’s fantastic that the IE team added PNG alpha transparency to IE7, but apparently they kept the gAMA bug in IE7 to make sure browser compatibility specialists keep their jobs for years to come.