Yeah, use Armbian. And Debian mainline and Arch Linux (ARM variant) run on the Cubietruck as well. Most of the stuff has been mainlined. I just can’t get graphics acceleration working. Other than that you could just install any regular Linux distribution. If you’re willing to put in the extra effort to deal with u-boot or whatever we use these days and the other effort involved to put Linux on an ARM computer. There’s info on their Wikis. And https://linux-sunxi.org has some information as well. Most of the times general instructions for A20 boards apply.