leopard.sh: a package manager for OS X Leopard (10.5) PowerPC, written in Bash
The two existing options for building open source software on Tiger and Leopard are Tigerbrew and Mac Ports, but I've been frustrated by how opaque their formulas can be (particularly when trying to diagnose and fix a failing build).
So I decided to write the simplest, flattest (in terms of abstraction) package manager possible: just a plain old series of Bash scripts (with another script which fetches and runs them).
See the leopard.sh repository.
(I'm also starting to tinker with
tiger.sh, but that isn't as far along yet.)
UPDATE: see also http://leopard.sh