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.
dbMan is a complex SQL monitor for common database systems (PgSQL, Oracle, MySQL etc.). It's based on Perl and DBI interfaces. Features include a command history buffer, tab completion, editing Oracle objects, simultaneous connections, SQL help, importing and exporting of tables, Oracle explain plan, and more. dbMan is made as a simple kernel and many extension modules, and you can make your modules with a simple HOWTO.
DBPrism is an open source framework to generate dynamic XML from a database. It connects Oracle databases with Apache Cocoon, providing a high performance DBGenerator with functionality such as parallel content aggregation and ESI cache protocol. It also includes a powerlful database oriented CMS built on top of Apache Cocoon2 and DBPrism.
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.
refbase is a Web-based bibliographic manager that can import and export references in various formats (including BibTeX, Endnote, ISI, RIS, PubMed, MODS XML, OpenOffice, and Word 2007 XML). It can make formatted lists of citations in HTML, RTF, PDF, or LaTeX, and offers powerful searching and RSS support. Its OpenSearch and SRU/W services and support for unAPI and COinS metadata allow for easy access by clients and search engines.
Babase is a baboon data management system. It is designed to facilitate the retrieval, storage, maintenance, and analysis of the following broad data categories: group membership, social status (dominance rank), life events, sexual cycle events (including progeny), sexual cycle day-to-day status, dyadic social interactions, focal animal samples, and multi-party social interactions. Integration of other data is supported. Babase is designed for Web access.