This is one of my most significant private projects ever. Its a fully functional real estate database, with a web interface to allow access by anyone to the companies sales information on properties. It uses MySQL/PHP as its basic engine, but also has significant amounts of JavaScript, HTML (of course), CSS, and shell scripting. The combination of these 6 scripting/layout languages allows almost anything to be done quickly and reliably.

The biggest time saver for them is the picture upload and processing system, which uses ImageMagick to automatically process images which had to be processed manually in the previous system.