GBuild is a set of makefile macros built on top of gmake that attempts to simplify LibreOffice development.
See
https://wiki.documentfoundation.org/Development/Build_System
for online build-system documentation.
See
https://web.archive.org/web/20130911015536/http://wiki.openoffice.org/wiki/Build_Environment_Effort/Module_Migration
for an archived overview of the new build system.
See
./solenv/doc/gbuild
for a commented class/API hierarchy of gbuild written in C++ syntax. It was not
intended for any use beyond to generate nicelooking docs with the doxygen
doxygen documentation generator from it. It likely is quite outdated these
days.