If you want a more lightweight server-side software that can access Fediverse, I found two good candidates (I am looking for other suggestions):
- GoToSocial: https://docs.gotosocial.org/
- Pleroma: https://pleroma.social/
- GoToSocial: https://docs.gotosocial.org/
- Pleroma: https://pleroma.social/
GoToSocial: 6849 files plus dependencies
Pleroma: 2289 files plus dependencies
283 files
Still crazy many, but I will look a into it in case https://microblog.pub turns out to be not what I am looking for.