Continuing my series of posts about random fediverse servers discovered in the wild, here is another one that looks promising, written in Crystal

"Ktistec is an ActivityPub server. It is intended for small numbers of trusted users (everyone is an administrator). It is designed to have few runtime dependencies -- for example, it uses SQLite as its database, instead of PostgreSQL + Redis + etc"

https://github.com/toddsundsted/ktistec/