Lattice is a Java build system with strong multi-module support. Build files are written not in XML, but in the Python language. The benefits are much better readability and powerful imperative build scripting. For multi-module projects, Lattice uses topological sorting to decide the correct order to build each module. Because a custom task is just a regular Python function, they can perform any type of work, including invoking other Java build systems such as Ant, Maven, or Ivy.