I have tried a number of desktop feed aggregators, but I found that I liked reading planets in Firefox best. Recently, hearing all the buzz about DHTML applications taking over the world, I decided to try and learn some JavaScript, and also make my planet more useful.
The result: Planet Mg now lets you collapse stories you have read, and remembers collapsed stories in a cookie. You can also move around stories with the keyboard (press ? for a list of key bindings). There are also unit tests for the JavaScript code.
Not everything works in Internet Explorer, though. I don't really need MSIE compatibility on Planet Mg, as its intended audience is just one Firefox user (me), but it would be a good exercise. I will work on it, time permitting.
I would like to thank Jeff Waugh, Scott James Remnant and other Planet developers for Planet; Chris Dolan for the inspiring JavaScript on his planet; Edward Hieatt for JsUnit; Peter-Paul Koch for QuirksMode.