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.
Orac is a GUI tool for Database Administrators written in Perl, Tk, and DBI. It organizes many useful DBA scripts into a nice graphical interface, for collecting statistics on your database, or diagnosing problems. It currently supports Oracle, Sybase, and Informix. Richard Sutherland's DDL::Oracle Perl module has been integrated with the current version for the Oracle side of things, greatly improving the Oracle developer options on the program.
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.
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.