The latest release, 1.2.0, compiles relatively easily under Mac OS X, once you have Xquartz installed. It's not a native port (it uses X11), and does not have sound, but works well otherwise.
The code on the "future" branch is trickier to compile, but uses SDL, so it has native graphics and sounds. It seems to work ok, but it has all sorts of half-baked changes, so there's some risk of crashes... :-)
They're both compatible at the network level, so you use one or the other to participate in Internet games just as well.