Internet Explorer is still one of the most used browsers on the planet with it having a bigger chunk of the browser pie than any other browser. The main reason for this of course is that it comes with Windows, so for many they won't know of the alternatives and for a long time there was no real alternative until Firefox came along. As much as I hate to admit it, back then when version 6 of IE first came out it was the best browser to have at the time.
These days Internet Explorer is lagging behind so far that even in the most recent IE8 there are still divergencies where Microsoft have not conformed to the standards set by the W3C. Of course, IE6 being long in the tooth now was far worse than this and had many nuances where IE6 has just done it's own thing instead of what it was supposed to. This has plagued the browsers very existence and has caused many a lost hour for web designers and developers alike.
It's time now for people to move on past IE6 - it is true there are still some people using it, but with a gentle push they can be convinced to move forward to "proper" browsers; even if it is only IE7 or 8. It is this ideology, a world without IE6, which has spurred on a number of new sites to spring up in the past couple of weeks such as ie6update.com and the ie6-upgrade-warning submitted to Google Code. Of the two I actually prefer the former as it will still allow the user to browse the site and I think it's more subtle and stands a better chance of it convincing users to upgrade as it's styled like the alert bars you normally see in IE.
