A little know fact about IE8 is that it came with a built in content blocking mechanism appropriately called Tracking Protection way back in 2009. IIRC it was the first browser to come with ad blocking built in, although not turn on by default. Opera came with content blocking a bit later.

IE9 improved on it with what I think is one of the most impressive feature to this day. It had a heuristic tracking protection that block trackers once it's detected at a certain re-occurrence counts that you can config. So in theory it doesn't need to subscribed to an ad list like all browsers do today.

IE took a lot of crap deservedly so, but that overshadowed a lot of pioneer works that later browsers adopted.