CPAN is the Comprehensive Perl Archive Network. It's accessible via the command line by executing "cpan". As long as you have a functioning perl install (a prerequisite for MogileFS) you should have CPAN support.
MogileFS releases are uploaded to the CPAN at regular intervals, and is comprised of several packages:
There are many other supportive packages, and is a good idea to look at all of them.
cpanm is a swanky way to do local builds of MogileFS. Combined with local::lib you can pull an install into a user's homedir instead of the base OS.
You can even use it without installing cpanm:
$ wget -O- http://xrl.us/cpanm | perl - MogileFS::Server MogileFS::Client MogileFS::Utils
... will fetch cpanm, execute it, and fetch/install dependencies as well.
The install of these modules is fairly straight forward. If you've never ran CPAN before, you'll be guided through a simple configuration and then be ready to go.
$ cpan
cpan[1]> install MogileFS::Server
...
That's all there is to it! Of course, if you need MogileFS::Client type that instead of MogileFS::Server.