I ran into Gemini last week looking into lightweight markup languages and Gemtext seems like an interesting one.

Gemini really does seem like a heavy handed approach (in a good way) to creating a pure hypermedia system and avoiding the road HTML went down. No Code-on-demand constraint, no concept of styling at all leaving display totally up to the client removes a ton of the complexity. I saw Gemini defined as "a better gopher" and think that's fairly accurate.