Hugo is written in Go, hippy enough for me. It was my first experience with static websites, and I was surprised how smooth it is: easy installation, easy testing, easy deployment.

I was disappointed how Gitbook, after going the SaaS way with v3, has broken compatibility with their own v2 cli. If you export markdown files from gitbook.io, gitbook-cli v2 is unable to import them and turn into static HTML files because Gitbook now uses custom liquid tags which are not open-source.

There's a fork of gitbook v2 https://github.com/honkit/honkit

not sure how well maintained it is though

MdBook is another good one, as hip as it goes, written in Rust nonetheless :-)

Jekyll is written in Ruby, but you're right that being used for Github pages makes it popular.

m000 is saying that the usage of Jekyll (Ruby) and Hugo (Go) are driven in part by hip trend-following programmers not wanting to use Python, not that Jekyll and Hugo are written in Python.

Right, I think the counter here is that Ruby isn’t trendier than Python is.

Not anymore, but it sure used to be, around the time Jekyll came into the mainstream.