The TriggerTool graphical user interface to the ATLAS trigger configuration database

The ATLAS detector at the LHC uses a three-level trigger system to select events of potential interest from the 40 MHz proton-proton collisions, thereby reducing the data rate to a manageable level. A system has been designed and implemented to configure all three trigger levels from a centrally provided relational database, in which an archive of all trigger configurations used in data taking is also maintained. The user interaction with this database is via a Java-based graphical user interface known as the TriggerTool. We describe here how the TriggerTool has been designed to fulfill several different roles for users of varying expertise, from being a browser of the database to a tool for creating and modifying configurations.