prjx/os is an OS for cheaply and easily running server applications at home. Raspberry Pi3 and x86_64 PC are currently supported.
A high-level description is available here: https://opensource.com/article/18/3/host-your-own-email
The current state is between Proof-of-concept and Alpha. Installable images will be provided once things are closer to Beta quality, for now, you have to build from source. If you'd like to be notified when images are available, email firstname.lastname@example.org and we'll let you know.
We have a IRC channel: #prjx on Freenode.
Nolan gave a talk at SCALE16x in Pasadena: Slides: https://sigbus.net/prjx_scale16.pdf
Talk video: https://youtu.be/9t4aMPF1UYU?t=8554