The PyMOL installation process is slightly different for each platform.
First, you must download the latest build for your platform.
There are several different ways to run PyMOL on the Macintosh. The following information pertains to MacPyMOL, the native-like port of PyMOL for Cocoa.
tar -jxf pymol-X_XX-bin-linux-x86-glibc23.tar.bz2
to create a pymol directory.
cd pymol ./setup.sh
to create a pymol launch script.
./pymol
Information about how to compile the PyMOL from the open source code can be found on the PyMOL Wiki.
Regarding Compilation under Microsoft Windows
Microsoft Windows, as a proprietary closed-source operating system, is not a supported compilation environment for Open-Source PyMOL. While Windows compilation is of course possible and allowed, it is defined as “beyond scope” for the open-source project. Thus, to use current versions of PyMOL on Windows, you must either sponsor the project in order to access precompiled executables or create, maintain, and support your own port for Windows, preferably via Cygwin .
Regarding Compilation under Mac OS X
Although Mac OS X is a proprietary closed-source operating system, compilation of PyMOL is supported on Mac OS X under the X11/Fink environment, since that setup is directly compatible with what you'd find on Linux or FreeBSD. Do note however that the resulting executable will not have the integrated single-window user interface available in MacPyMOL.