Ant

Jakarta's Apache Ant is a widely used tool for building java application.
In the same category are there msbuild, make - the ancester of the it's kind, are there also NAnt (for .Net, generate msi installer) and .Net Ant Library. It looks it is going to combine with unit testing frameworks as well.

In the essence, Ant helps build an application by doing a series of steps, including compiling source code, creating target folders and copying files etc.

Ant does all these based on an xml formatted build file, or files - one master and a number of subordinate build files. By adopting xml as the build authoring format, it provides benefits like open standart to conform, easy to add new vocabulary and more.

An xml build file consists a number of targets and each target consists of a number of tasks. A target is a bigger work unit and a task is a single step to accomplish a target.