BSDBuild is a simple, self-contained and portable build system derived from the
traditional 4.4BSD share/mk files. BSDBuild uses BSD-style makefiles, but
without BSD make extensions (it uses standard Bourne script fragments instead),
so the build system is portable to most operating systems and make flavors.

Because BSDBuild is implemented as a library, Makefiles never need to be
recompiled (unless a separate build is requested). BSDBuild can also generate
pure Bourne ./configure scripts, which function similarly to GNU-style
configure scripts (as far as end-users are concerned), but are compiled using
Perl modules instead of macro packages.