The best web browser around, maybe even ever. Comes pre-installed with Windows, and has awesome features built into it, such as a popup blocker, private browsing, and link scanning. Definitely the top of the line in terms of technology, compared to its rivals.
Competitors include Firefox, Opera, and Google Chrome, but they all take up way too much memory, and have a bunch of useless "add-ons" that you have to install just to do basic stuff such as block popups. These addons frequently cause browser crashes, and become outdated whenever the browser updates. IE8 comes with all of these features from the start, and the addons it has never cause problems. Internet Explorer can also view 99% of all websites with no problem, while these other guys are incompatible with half of the websites out there.
Some douches out there will dis Internet Explorer, but usually these guys are just butthurt Mac fans who are jealous of Microsoft's popularity - so don't listen to them, Internet Explorer is the best.
Retarded Firefox user: "Internet Explorer sucks compared to Firefox - Firefox has this cool addon that lets me watch gay porn while listening to Boy George music in the same window... (addon crashes) ... AAAGGHHHH!!!
Smart IE8 user: Wow, grow a brain idiot. Don't be jealous just 'cause you got suckered into buying a Mac and got stuck with Firefux as your default browser. Internet Explorer kicks ass.