The defining aspect of Internet Explorer’s impact on the WWW is that, once Microsoft killed Netscape and Internet Explorer 6 gained >95% market share, they shut

The defining aspect of Internet Explorer’s impact on the WWW is that, once Microsoft killed Netscape and Internet Explorer 6 gained >95% market share, they shut down development for five years. When Firefox started to become popular, they restarted development. That’s more than five incredibly long years where front-end web development was dragged down to an absolute standstill by Microsoft. Even the subsequent Internet Explorer 7 was just a quick patch job to fix the weirdest rendering bugs, add some CSS selectors, and add tabs. It wasn’t until Internet Explorer 7 (released in 2006) dropped out of use that web developers could rely upon post-2001 CSS, and it wasn’t until Internet Explorer 8 (released in 2009) dropped out of use that web developers could rely upon post-2001 JavaScript. In that entire 2001–2006 span, the most significant forward motion that happened was a slight change to how a couple of HTTP headers were handled if the user had installed Windows XP Service Pack 2. Safari, even on its very worst day, is not even remotely on the same scale as the horrific effect Internet Explorer had on the industry. Anybody telling you that “Safari is the new IE” simply has no clue whatsoever what Internet Explorer was like to deal with back in the day. Browser support for absolutely everything was at a complete standstill for most of a decade because of Internet Explorer.