Database management in a single PHP file
Open Source Document Management System
Simple, modern & fast web-based email client
Superseded by the official Gimp release: http://www.gimp.org/downloads
LGSL (Live Game for PHP 5.4-8+: online status for various gameservers
phpwcms is a web content management system
Allow to redirect (a.k.a. "remail") mail messages to other recipients
Monsta FTP is a delightfully intuitive web-based file manager.
OXID eShop is a trusted and flexible open source e-commerce system