Graphserver is an excellent piece of software, especially for working with OpenStreetMap data (my latest obsession).
To get it up and running on my Mac I needed to make some very minor tweaks to the Makefile. I haven't been able to run the test suite (odd issue with nosetests on my machine), but the example scripts seem to work correctly.
Here's the Makefile patch, apply it to graphserver/core/Makefile and run make.