From the page style:

    textarea {
       font-family: monaco, courier, monospace;
       width: 500px;
       ...
    }

Web designing mistake, wrong choice of units. Depending on user's choice of font width, text will wrap inside the text area and not produce the expected result. 'width: 40em' would be a lot more sensible and produce the expected results.

This needs to be at the top of Hacker News.

Thank you for providing me with this internet-essential service. You are a true hero, tpope.

I hope this makes it into CSS3. Is it too late?

Quick, somebody do text-align: weft and text-align: wight!

this is about 100 times more useful than colour.com

Gah! Again IE 7 Fail! That's it I'm quiting this job and going somewhere where they don't care which browswer I use!

It's cute, but why do people buy domains for things like this?

If your karma is under 100, you should be unable to post links. This is just further evidence.