GMAT uses a CMake configuration for building the system on all platforms. See the Cmake documentation here for complete details: Using the GSFC-Internal CMake Build System
Obsolete Build Systems
These build options are obsolete but we're keeping the documentation around while everyone migrates to Cmake
How to Build Scripts on Windows 7/8, Linux Ubuntu 12.04 and Macintosh OSX Lion systems
Here are instructions about Building GMAT on Windows, Linux and Macintosh systems.
How to Use the Build System
Here are instructions for advanced users about how to use the Build System.
GMAT has a simple static build Solution for Microsoft Windows Visual Studio 2010 Express. This is not well documented but it is often used by developers for debugging.