Since writing this article in 2004, I’ve found that best practise is to use valid HTML 4.01. Also, W3C will work on an HTML 5 specification. So the “future-proofing” of HTML is looking just rosy.

Furthermore, XHTML only has singificant benefits when labelled with the application/xhtml+xml MIME type. However, many devices do not support this type of transmission such as such as Internet Explorer 7 and lower, along with many mobile phone browsers. You’d have to produce an HTML version for people using these devices.

Furthermore, the complexities of authoring proper XML are way beyond me. If you can’t meet its exacting requirements, the best bet is to write HTML 4.01 Strict. That’s what I’ve now been doing since early 2006.