Ant

Despite its widespread use, Ant is ultimately inadequate as a build system. In some ways, it is well-suited for building simple Java projects: It is integrated with the JVM and extensible in Java, and it has an established library of code for a variety of tasks. Unfortunately, there are core responsibilities of a build system — keeping track of dependencies among files and rebuilding only as necessary — that Ant simply does not perform, delegating instead to every individual task to do what should be core functionality.