TeX Line breaking algorithm in JavaScript, awesome and well-readable.
Top Crashers By URL for Firefox 3.6, mostly Flash.
Raw Meat is Aaron Swartz’s tumblelog.
Vimium is a Chrome extension that provides keyboard based navigation and control in the spirit of the Vim editor.
MuPDF is a lightweight PDF viewer and toolkit written in portable C. Very fast and of high quality.
Pino is Twitter client for Linux desktop. Best one I found so far, and fairly lightweight.
ShadyURL, don’t just shorten your URL, make it suspicious and frightening.