The Validator isn't the end
I’ve been very busy recently, so just to pass the time here is something interesting I found on the internet that shows the importance of human error-checking for HTML markup, instead of just relying on a DTD-based validator such as the W3C’s to validate the document.
http://www.webdevout.net/testcases/valid-but-wrong/html.php
Well, I suppose some of you may remember the days when the whole department only had one compiler, with the queue many hours long, and if there was something wrong with your code, you had to forfeit your place and manually debug – letting the machine do it just wasn’t a viable option.