This page uses the "hidden radio button" hack to enable its show/hide functionality without any javascript at all.

Click on the language tags right here at the top to show only a single language. Each of the tags is really a label for a display:none radio button placed right before it in the page.

Based on the :checked pseudoclass, I then bold the label and show/hide things in the list. Again, this is all pure CSS, no javascript at all.

Of course, this doesn't currently work in any IE - it requires support for both :checked and :not(). But any modern version of the other major browsers should work.