HTML and CSS are used in all my web design work, and have been for many years.

My commercial use of XML thus far has been solely with PHP to get data into a database, and I have not yet used XML and XSL on a serious site. The reason for this is that, to date, the page would not be viewable to many visitors to a site - particularly search engine spiders, and so for commercial use, the two have to be combined server side, which, if you have a lot of pages, makes the server work much harder than it ought to.