Combine dependency-resolution, lazy-binding and rake (a ruby-based make alternative) and you get filament. Filament workspaces are a simple, cross-platform approach to managing complex build needs.
I created it satisfy my needs as a mobile application developer.
I am currently managing a number of inter-dependent libraries for a suite of JavaME platforms using only filament, its stock plugins, and minor dependencies.
This tool has been developed and tested on Ruby 1.8.4, Rake 0.7, Cygwin (XP sp2), OS X 10.4.5, and Gentoo Linux.