Microsoft's Internet Explorer provides a huge set of features for the Web developer. They can be put to good use in many types of applications. However, I guarantee you that some folks (especially teenage girls who get a whiff of some MSDN documents about filters and transitions that I will leave to the reader to find) will use these "gems" on their Web pages and create a new category of Web Pages that Suck: IE-Only Flashturbation.
Maybe it's not Flashturbation, since these tricks make no use of Macromedia's infamous animation and Web application format. But it's still about as tacky as a chair coated in honey.
Five of these techniques, in order from least to most potential for abuse, are colored scrollbars, page transitions, gradient backgrounds, image alpha blending, and conditional comments.
Colored Scrollbars
One of the many "improvements" to Internet Explorer 5.5 was the ability for designers to change the scrollbar colors. This trick presents no problem to users of other browsers, but those who do use IE5.5+ may end up being confused at the changing of their scrollbars. Some real moron could set the scrollbars up to be invisible and cause a ton of chaos at the client side.
Page Transitions
Page transitions cause a page to transition in or out in Internet Explorer. This doesn't work in other browsers, which is actually a blessing: A transition can be set up to literally take minutes, or even hours; even if they're only set up to take a second, the transitions are usually dumb and perhaps slightly gay. Raiderpride.org is an example of a site that uses page transitions.
Gradient Backgrounds
Another IE5.5-ism is the ability to have gradient backgrounds in a page. The background could become a dependency and end up making a page unreadable to non-IE-users, but it definitely will slow things down quite a bit. It's also buggy in IE5.5 (the background doesn't really appear in some cases unless you scroll the window).
Image Alpha Blending
Image alpha blending, which can make images translucent or transparent, has the most potential for abuse. Why does it have a high potential for abuse? The answer is that someone can overlay a blocking image over another one and make the blocking image transparent to IE5.5+ users. Those who use other CSS-compliant browsers will see only the blocking image. Needless to say, this has the potential to be an effective way to lock out non-IE-users.
Conditional Comments
If you saw my welcome page in IE 6, you probably noticed that the menu had the text "Hey IE 6 User! You may want to try a real browser." at the bottom. The code for that was put into a conditional comment. Conditional comments can be used to block out code. Internet Exploder reads these comments and unblocks the code if the comment block's condition is true (i.e., the browser being used is a version of Internet Exploder specified by the comment).
This means that some dimwit can go and block his whole page behind a conditional comment, and only Internet Exploder users can see it. The dimwit may also block versions of IE and give them the same effect as the people not using IE.
However, for some reason, Arachne will render code in these comments just like the "right" version(s) of Internet Exploder would.
Demo:
If you are using Internet Exploder 5.5 or 6, this demo page will show you exactly why these techniques are a bad idea to use. WARNING: the entrance transition is set to take 60 seconds!
Notes:
This is more IE bashing. But it does prove a point that needs to be proven: stupid proprietary tricks are dumb and tacky.