It turns out this snippet of HTML:

<input type>

crashes Internet Explorer. Try it.

dive into mark has a long comment thread about it, which of course devolves into anti-monopolistic rants against Microsoft. As much as I dislike Microsoft's business practices, I don't think they are inept at creating software (far from it, and it makes me even more baffled as to why they have to act like such aggressive bastards on the business side). It's just amusing to see such a simple input crash IE.

And for balance, this snippet:

<fieldset style="position:fixed">
<legend>Crash</legend>
</fieldset>

crashes Mozilla-based browsers. Try it.