NetRenderer is a service that will show you how web pages display using Internet Explorer versions 5.5, 6, and 7. This is a great, great tool for web page design, especially since pre-7 versions of Internet Explorer are notoriously tricky to design style sheets for.
IE has been much improved of late, and Microsoft recently announced that the forthcoming IE version 8 has passed the Acid2 test! (also: Acid2 on Wikipedia)
found via LISNews
