Fink

Download and install fink as usual. Did install the latest X11 for Leopard linked from fink site.

install:
arb
bioperl
biopython
 
biopython has clustalw as a dependency. To get arb and clustalw to play nice, edit:
sw/fink/dists/unstable/main/finkinfo/sci/arb.info
and remove apropriate packages from "Conflicts:" line.
Then install final conflicting package with something like:
sudo dpkg --force-overwrite -i arb_20071207-1005_darwin-i386.deb

 

To get arb pt_server working:
ln -s /sw/bin /sw/share/arb/bin

edit /etc/hosts.
Change:
127.0.0.1    localhost
to
127.0.0.1    localhost    rocapws.ocean.washington.edu