NAnt is described as 'free .NET build tool. In theory it is kind of like make without make's wrinkles. In practice it's a lot like Ant' and is an app in the Development category. There are more than 10 alternatives to NAnt for a variety of platforms, including Linux, Mac, Windows, BSD and Android. The best alternative is CMake, which is both free and Open Source. Other great apps like NAnt are GNU Make (Free, Open Source), SCons (Free, Open Source), Maven (Free, Open Source) and Gradle (Free, Open Source).
SCons is an Open Source software construction tool—that is, a next-generation build tool. Think of SCons as an improved, cross-platform substitute for the classic Make utility with integrated functionality similar to autoconf/automake and compiler caches such as ccache.
Apache Maven is a Java-based tool for build automation and project management (in software development). It is centered around a Project Object Model (POM) described in a XML file that describes the project structure and its dependencies to other components and libraries.
Gradle is build automation evolved. Gradle can automate the building, testing, publishing, deployment and more of software packages or other types of projects such as generated static websites, generated documentation or indeed anything else.