Turbine is a servlet based framework that allows experienced Java developers to quickly build web applications.
XML-RPC is a Java implementation of XML-RPC, a popular protocol that uses XML over HTTP to implement remote procedure calls.
Commons Exec is a project for running OS processes from within your Java application
Commons Email aims to provide a API for sending email.
JSPWiki is a Java based wiki and Siegfried tinkers with the idea of a "Wiki On A Stick"