Via this post on Nexen.net today, they point out this interesting bit of PHP software - myColex.
myColex is a complete museum management and collection documentation system with longterm archiving capabilities based on Apache/PHP and mySQL. Manage your object inventories, events, pictures, addresses e.g. with your browser.
It hasn't been updated in a while (06.2004), but it's an interesting niche market for a PHP application, and it really goes a long way to show the flexibility the language has...