Ariadne is a Web Application Framework and Content Management System built with PHP. It allows you to build complex Web applications and sites with ease. It takes care of the mundane stuff like internationalization, security, user management, templating, data retrieval and storage, caching, and site management. It stores content in a structured object store that can be accessed through an extensive filesystem-like API.
Foswiki is wiki software, supporting the editing of Web pages in an ordinary Web browser by end users. What makes Foswiki special is that it supports the embedding of active and passive macros that enhance the page content (e.g. with global or dynamic information) and allow end-users to build applications that store and process data in a structured manner.
papaya CMS is a Web Content Management System based on open standards (including XML, XSLT, PHP, and MySQL/PostgreSQL). It is compatible with almost every operating system, is platform-independent, is multi-lingual, offers great usability, and is easy to extend via its plugin system. It is scalable and perfect for business websites.