Update: (November 2019) I am now serving mostly XHTML5 and also serving it as application/xml+xhtml.

I feel that validating against an XHTML schema makes my code cleaner and less buggy, because I need to have closing tags, as well as use a trailing “/” for standalone tags, etc. I also find the additional XHTML 1.1 restrictions to be a good idea.

Therefore I decided to make XHTML 1.1 the default doctype for the pages on my site. The reason I’m serving them as text/html is because Microsoft Internet Explorer does not handle application/xml+xhtml properly, and I’d rather not needlessly discriminate against people who still use it (possibly against their will).

I realise that it stands against the XHTML standard, but I’m not a standards purist, and want to be a bit pragmatic in still supporting Explorer. Note that some pages in the Math-Ventures section end with the .xhtml suffix and are served as XHTML because they contain MathML.