Mailman currently runs only on GNU/Linux and any other Un*x-like operating system, such as *BSD, Solaris, etc. It should work on MacOSX but not earlier versions of MacOS. It probably does not work on Windows, although it's possible you could get it running on a Cygwin system (please let the developer community know if you have success with this!)

Before you can run Mailman, you need to make sure that Python is installed. Mailman 2.1 requires at least Python 2.1.3, although Python 2.2.2 is recommended. Most GNU/Linux systems come with Python pre-installed, so you just need to make sure you're running an up-to-date version. You can do this by executing the following at your shell's command line:

% python -V
Python 2.1.3
If your Python executable doesn't understand the -V option, it's definitely too old!

You will also need an SMTP server (a.k.a. mail transport agent or MTA) for mail delivery and reception. Mailman should work well with any of the most popular Unix mail servers such as Postfix, Exim, Sendmail and qmail.

You will also need a web server. Apache is certainly the most popular, is available for all Unix systems, and works great with Mailman.

To install Mailman from the sources, you will also need an ANSI C compiler. The GNU C compiler gcc 2.8.1 or later is known to work well.