When I first decided to hack furigana for the web, I simply used HTML tooltips, with a bit of CSS to highlight the glossed word. It mostly worked, but the presentation was iffy, and by default IE didn’t use a Unicode font for tooltips. I also knocked together a script to simplify the process of marking up a lot of text; that one needs some more work, still.
After my recent discovery that IE7 is still hosed for basic CSS, I broke down and cleaned up my JS code, and I’m going to start using it. Here’s the first test: 漢字には全てふりがなが付いています。
[Update: hmm, the offset function in the new version of the jquery dimensions plug-in isn’t calculating the correct bounding box for the base text in IE 6. I’ll have to look at that. However, the ifixpng plug-in does finally make my site logo work in IE6.]
[Update: I’m behind the times. offset() has been rolled into the core jquery library, and it’s fine; the problem was that IE6 doesn’t bother calculating changes to a hidden DIV. If I show it and then update its position, it works fine.]