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.
Meson aims to be the most usable and fast build system. It provides a simple yet powerful mostly declarative language for describing your build. It has native support for modern tools and frameworks, such as Qt5, code coverage, unit tests, precompiled headers, and others. It utilizes a host of optimization techniques to compile your code faster on both full and incremental builds.
crumb is an experimental build-automation program to provide functionality similar to "make" but with a much better approach, where dependencies for all invocations are automatically detected, by using shared-library level hooks. The spawned processes are also paused if a missing dependency needs to be generated. Oddly, with parallelism, this means that the linker might run before the compiler, but it will get paused until the compiler is done generating the input that it needs. Another purpose of crumb is to provide users with absolutely minimal build description files. This means that the build description files need to be smaller than an equivalent shell script containing the commands that would have built the project directly.