Enzyme is an architecture for creating user-searching-user applications. Right now, it is primarily useful as a resume create/search and HR management system. However, it's potential uses are wide-ranging, and it offers PHP developers an alternative to relying on simple "keyword" searching systems.
PostNuke is a Weblog/portal system featuring an extremely easy-to-use Web-based installation script. It is extremely developer and community friendly, with active development progressing, support forums around the world, and live support via its own IRC network. It was originally based on PHP-Nuke, but was rewritten with security and performance in mind.
Permission Record Information Machine (PRIM) delivers database connectivity via a web browser. Users can have different database permissions (e.g. create tables, modify tables, etc.). PRIM has built-in database analytical tools such as graph displays, reporting, etc. English and Chinese (Big5) language support.
The goal of the X-itools project is to propose an alternative to products like Exchange or Lotus Notes/Domino. They are composed of several modules, and this project has been under development for several years. Modules include a shared public and private agenda, a flow-chart, task, and post-it manager, a visitors and associated badges manager, a password and history manager (with the ability to encrypt things other than passwords), a holiday manager (to manage public vacation days, illness periods, absence periods according to country profiles), a shared public and private address book, an incoming and outgoing phone calls manager, and a global management module.