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.
TYPO3 CMS is a Web Content Management System which features automatic creation of navigational menus, headlines, and other dynamic graphical elements, automatic conversion and scaling of images, the ability to present different templates based on variables such as client browser or country code, support for multiple templates on a site, and a built-in password-protection option. Pages can be timed to be shown on a certain date, be hidden on a certain date or just temporarily hidden. TYPO3 supports search in SQL-databases and redesigning of a website at once is just a matter of creating a single new template.
PHPX is a Web portal system, blog, Content Management System (CMS), forum, and more. It is designed to allow everyone to be able to have feature-rich, interactive websites even if you do not know a bit of programming. Some key features include fully-integrated forums, downloads, an image gallery with slideshow and auto-thumbnailing, support ticket system, a GUI interface for Web page content management, news with topics and instances, and a whole lot more. It allows you to fully customize the look of your site.
SearchAssist is a simple but practical search engine application that uses a ternary search tree. It uses Java's dynamic loading feature to make the search engine highly customizable, and uses takes Mozilla bookmarks as input. A Swing UI allows users to enter search words and view the results.