But I don't have **apt** or **apt-get** tools available on the ATV. I used the standard settings on ATBUSB-Creator, which included "binutils", which I would have thought included them. Should apt be loaded through ATVUSB-Creator, or have I missed another step somewhere?
I can't find instructions for how to use Greenpois0n with ATV Gen 1, so that's why I've not tried that route.
I have plex on ATV1 using CrystalBuntu and PleXBMC. It is a great combo, but it takes a little work to get going. Take a look at the CrystalBuntu site and the PleXBMC thread on here for more details.
I also have plex via plexbmc and openelec/KODI (formally XBMC) which is basically a small build of linux to specifically run XBMC. It is a well maintained series of releases that specifically addresses the appletv1. It works well but you have limited skins available. It's a real nice box but really getting a bit long in the tooth compared to newer offerings.
There is a generic build here, somewhere on this plex forum that incorporates openelec/plex directly. There are several builds but I haven't tried it as the author has removed support for the Broadcom BCM970015 CrystalHD card i have installed to help the Apple TV play 1080p videos.