There's a new very lightweight Fediverse platform that's just been released called littleFedi. You can follow its new official account at:
Its official website including download and source code is at:
LittleFedi is for techy people who want to create their own Fediverse server using as few resources as possible.
It's written by a group called "Little Computer People", its maintainer is @stefano
@homegrown @littlefedi_official @stefano
Excellent instructions on what is involved.
Will have to read in more detail.
Many thanks guys.