Weld is an implementation of a non-recursive build system on top of GNU Make. By avoiding recursion, Weld is able to define an easy to use, fast, and scalable build system. Buildable components are defined by writing an easy to read component definition file. Components are automatically discovered and their dependencies automatically determined. This perfect dependency discovery results in precise incremental builds and optimal parallelization among build tasks. Weld supports Windows, Linux, and FreeBSD.