Jailer is a database subsetting and browsing tool. It is a tool for data exporting, schema browsing, and rendering. It exports consistent, referentially intact row-sets from relational databases. It removes obsolete data without violating integrity. It is DBMS agnostic (by using JDBC), platform independent, and generates DbUnit datasets, hierarchically structured XML, and topologically sorted SQL-DML.
Lloyd's Java Shell is a java scripting tool (it could read and execute java-like statement from any input stream) that could easily be plugged into an application and modify its object - so it is also a configuration tool. It is also a good test tool, as you could easily use it to test any feature of your new object.
Trace.java is a package used by Java programmers, testers, server administrators and others to understand what happened during the execution of a program. It doesn't generate tracing statements automatically; programmers have to add them. Trace messages go into an in-core ring buffer, a disk log, or both. The disk log can be fixed size with backups. What amount of detail gets logged can be controlled at runtime or launch time. The ring buffer and disk log can be controlled separately. Different subsystems of the code can be controlled independently.
quizpool is a system for administering quizzes. The quizzes can be selected from pools of questions, written in "Question Definition Language", according to rules written in "Quiz Definition Language". When a user starts a session, they are presented with a menu of quizzes available. A quiz can then be selected and completed. If the user has not taken that quiz before, the number of chances they are given to take that quiz is randomly generated from the quiz pools for that quiz. This provides an even (or changing) mix of difficult, medium, and easy questions through the various attempts. All output is created from editable HTML template files, which are separate from the program code. This was developed under Apache and Boa.