I’ve been a fan of XBMC for many years, first on the original Xbox when it was called Xbox Media Center and now I’m using an ASrock ION330 with XBMC Live. Although there’s a small problem with my setup, it isn’t quiet. It doesn’t make a loud noise, but it’s far from silent. I thought to myself “hmm, maybe I should give Plex on my Apple TV gen 2 another go”. And that’s what I did.
Step 1 – Jailbreak

I used Seas0npass, you can read the jailbreak instructions here: http://support.firecore.com/entries/387605-jailbreaking-101-seas0npass
This was pretty much straight forward.
Step 2 – Configuring the ATV
Start by logging in to the ATV via SSH.
> ssh root@172.16.0.51
Change to your ATVs IP and use the password
alpine.
A jailbroken ATV uses the APT-system (same as Debian and Ubuntu) to install packages. There’s a repository for Plex that has to be added.
echo "deb http://www.ambertation.de ./downloads/PLEX/" > /etc/apt/sources.list.d/plex.list
apt-get update
apt-get upgrade
apt-get install com.plex.client-plugin
Plex is now installed. Make sure your Plex Media Server is running on your computer and then restart your ATV. Hopefully you’ll have a menu in your ATV that says “Plex” and you’ll be able to access your media.
My thoughts
Plex on ATV sure has a lot of good stuff going on, but it just isn’t there yet. I wasn’t able to play mkv-files, only XviD. The program itself is a bit buggy and crashes now and they, but the future for the project looks good. Can’t wait to throw my XBMC box out, but I think I’ll wait a while.