Charles Chan writes, "Even though Ant acts as the de facto standard for building Java programs, in many ways the tool falls short for project management tasks. In contrast, Maven, a high-level project management tool from the Apache Jakarta project, provides everything that Ant offers plus more."
Read this IBM developerWorks article by Charles Chan:
Nowadays, most developers recognize Ant as the standard build tool for Java programming projects. Unfortunately, Ant's project management facilities, as a replacement for make, fall short of most developers' needs. By examining an Ant build file, it's difficult to discover a project's dependencies and other meta information such as developers/owners, version, or site home page.
Maven, in addition to featuring program-build capabilities, offers high-level project management tools absent in Ant. Because Maven's default build rules are highly reusable, you can often build simple projects with two or three Maven build-script lines as compared to a dozen lines for Ant. Many Apache Jakarta projects, in fact, now use Maven, and the adoption rate for corporate projects continues to increase because of Maven's project-oriented approach.