My website automatically detects which language you prefer and displays the appropriate content. I’m using this script because I didn’t want to write one myself. Strict mode is of course off (be nice to IE ).
The website is delivered in either XHTML 1.1 or HTML 4.01 Strict. It depends on whether your browser accepts the application/xhtml+xml mime type. There’s a great script which automatically sends the right version to the browser. I’m using that script because XHTML should be delivered as application/xhtml+xml and I can’t just send it to all browsers as application/xhtml+xml, because there are some browsers that do not support this mime type (yes, IE again).