Soda is a course browser for Brown University, which has a very hard to use course system called Banner. This replaces Banner's complex interface with a simple search box and instant as-you-type searching. Soda also includes a shopping cart and schedule to help you plan your next semester.
It is written in straight HTML, CSS, and JavaScript. Brown's courses are gathered with a Python scraper and imported as a huge 6 MB JavaScript file, which GZIPs down to a little over 1 MB and is cached by the browser. Queries are compiled down to a regex and then just run through the huge list of courses. Search speed is not an issue in Chrome and Safari, but feels slower in Firefox.