Till Klampaeckel has a recent post about PEAR versus PEAR Farm on his blog detailing what each is and how to use the PEAR Farm to get your software out there.

With the release of Pirum, I'm really excited to see two public PEAR channels that aim to make PEAR a standard to deploy and manage your applications and libraries. One is PEARhub and the other is PEAR Farm. I think I'm gonna stick with PEAR Farm for a while, so this blog entry focuses on things I noticed when I first played with it. [...] A lot of people mistake these new channels for the wrong thing. They think that this will eventually replace PEAR. I don't think it will - ever.

He shows how to get the PEAR Farm libraries installed (via the PEAR installer) and how to set up your project with the pearfarm command-line tool. He also offers a few "gotchas" and tips to help you with a few of the issues he saw along the way. You can get an idea of the end result by looking at Till's PEAR Farm page.