I started my career 2008 building real estate and stock news websites. Back then, sooooo much of my days were spent making things "IE compatible" using techniques like: - creating sprite sheets of transparent png corners and sides that one could arrange in a table around an element to create drop-shadows and rounded corners - putting single pixel, transparent gifs at the end of floated containers because clearfix use…
I strongly remember using Firebug in Firefox (mind-blowing tools, for the time) in ~2008 and having to debug issues in IE, which had the equivalent of a Check Engine Light for debugging.
There was Firebug Light, which from memory was a bookmarklet that injected a cut down firebug into the page, but even that didn’t help much.