SchemaView Plus is a GUI for creating, retrieving, drawing, and printing database schema. It uses Perl, Tk, DBI, and XML packages. Schema can be retrieved using DBIx::SystemCatalog, and it uses XML for storing and retrieving data in text files. You can write any filters to modify these XML files to add new functionality based on your projects (e.g. dropping off some relationships).
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.
KorWeblog is highly customizable PHP/SQL Weblog/Content Management System initially based on phpweblog. Many features have been added, such as a FAQ, download, threaded comments, user-selectable site theme, user preferences, multi-login user support, story program, HTTP referer, browser/OS, and access counter in the stats page, anti-spam function, an IP blocking function, and more.
XMLDB uses an RDBMS to persist arbitrary XML documents. Due to its storage mechanism, searching for and recalling documents is extremely quick. You can also perform XSL translation on documents with surprising speed. The library can be used in any program to store libxml2 documents. A PHP module is also included, making XMLDB into a complete three-tier Web application development suite.