This document specifies the Gemini protocol for file transfer. It can be thought of as an incremental improvement over Gopher [RFC1436] rather than a stripped down HTTP [RFC7230]. It runs over TCP [STD7] port 1965 with encryption provided by TLS [RFC8446] with a simple request and response transaction.

So do I understand correctly that it requires TLS encryption? Won't that make it a lot less useful on any computer older than a few years?

Don't want to stop anyone else from having fun if this is what they like, but also the appeal of a simple protocol for text browsing (like Gopher) for me is that I can run it on an old computer as long as I can get the old computer online...