One of the best freely available build environment you'll ever see. It is part of OSE, which seems like a nice C++ package including a C++ library and a documentation extraction tool (similar to JavaDoc) in addition to the build environment.
It is built upon GnuMake, as a library of included makefiles and a few shell scripts. As such, it does not replace make, but rather supplement it with structure and easy-to-use small tools.
A typical fully-featured MakeIt file for all sources in a directory is about 5 lines long, consisting of just one or two settings and a very small boilerplate. Overall, a good tool.
You can get MakeIt at http://www.dscpl.com.au/. It's inside the tarball for the entire OSE project.
From RecursiveMakeConsideredHarmful (regarding MakeIt documentation): Yes, there is a postscript version. I've just added a link to it to the MakeIt page.
Where did said link go?
[Try http://www.inf.fu-berlin.de/projects/MakeIt/doc/documentation.ps.gz.]