ROOT on MacOS X

# rpm -ivh dlcompat-20021001-1a.ppc.rpm

if you haven't.

As of ROOT v.3.01.05, MacOS X is officially supported. We had, however, some problems with compiling ROOT on MacOS X10.2. These problems have been solved and necessary patches have been applied to the CVS tree. Consequently, ROOT v.3.03.09b and later should compile and run out of the box.
So now building "ROOT" is fairly straightforward.
Moreover the ROOT team now officially distributes a binary tarball for MacOS 10.2. If you just want to use ROOT, there is no need for your to compile it. The instruction given below is for those who might want to build it yourself.

[1] Compilation Conditions

MacOS X Release 10.2.3
standard Mach Kernel (Darwin 6.3)
gcc-with-g77-1175-1a
gcc-with-symlinks-g77-1175-1a
dlcompat-20021001-1a
Apple's X11 for MacOS X
freetype-*1.3.1-3c
CERNLIB-2002

If you want to try the current CVS tree, do

$ export CVSROOT=:pserver:cvs@root.cern.ch:/user/cvs
$ cvs login
(Logging in to cvs@root.cern.ch)
CVS password: cvs
$ cvs -z3 checkout root

or if you just want to use the production version, do

$ tar -zxvf ../orig/root_v3.04.02.source.tar.gz

then follow the steps below:

$ tar -zxvf ../orig/ttf_1.1.tar.gz
$ su
# mv ttf/fonts /usr/share/fonts/ttf
# pushd /cern/pro/lib
# ln -s libpythia6134.a libPythia6.a
# ln -s libjetset74.a libPythia.a
# exit
$ cd root
$ export ROOTSYS=`pwd`
$ export DYLD_LIBRARY_PATH=$ROOTSYS/lib
$ export PATH=$ROOTSYS/bin:$PATH
$ ./configure macosx
$ make

[3] Installation of a Precompiled Binary Package

Thanks to Fons Rademakers of the ROOT team, ROOT for MacOS X is now available as a binary tarball from the official ROOT site. All you need to do is expand the tarball in whatever directory you want to install ROOT.
For instance, if you want to install it as /opt/root/pro, do the following:

$ su
# tar -zxvf <somewhere>/root_v3.05.03.Darwin6.4.tar.gz -C /opt/root
# ln -s root_v3.05.03.Darwin6.4 /opt/root/pro
# exit
$ export ROOTSYS=/opt/root/pro
$ export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:$ROOTSYS/lib
$ export PATH=$PATH:$ROOTSYS/bin

Then adjust the directory for ttf fonts by editing ~/.rootrc, for instance, as:

#Unix.*.Root.TTFontPath:     $(ROOTSYS)/ttf/fonts
Unix.*.Root.TTFontPath:     /usr/share/fonts/ttf