2do is a simple to-do list manager written in PHP and using a MySQL database backend. It supports unlimited numbers of projects, has templated HTML allowing for complete customisation, and can be publically viewable by all, or can be protected by passwords. Administration is done via simple Web-based forms.
Kaolak is a Web-based community system. A Kaolak community is defined by its users and documents and forms a Kaolak branch. Kaolak is designed to handle many branches transparently from each other, within a single instance (one URL, one database). It features a permission scheme which allows users to give read/write access to documents they own to other groups/users. With a little PHP knowledge, modules can be implemented to extend Kaolak functionality.