Ant is an open source build tool (a program for putting together all the pieces of a program) from the Apache Software Foundation. The utility is the most commonly used build tool for programs written in Java. Although similar to the GNU make utility that it replaces, Ant is said to be more portable and simpler to use. Unlike many other build tools, Ant is independent of both platform and development environment.
Make (the most common build tool) and most alternatives are based on a particular shell or command interface, and for that reason are limited to the type of operating system that uses that shell. Ant uses Java classes rather than shell-based commands. Developers use XML to describe the modules in their program build, what those modules should do, and any dependencies between them and other parts of the program. Ant determines the parts of the program that have been changed since the last compilation, as well as any parts of the program that are dependent on those components, and then compiles only those parts that require it, in the proper order.
Ant is part of Apache's Jakarta project. Software consultant James Duncan Davidson created Ant on a transatlantic flight in 1998. Davidson was working on a cross-platform program build and running into problems using available build tools, so he created his own. Davidson said he named the tool "Ant" because it is a little thing that can build big things.