Any good public documentation tools?

What was lacking in the options you found?

I'm building something if you are still looking for a solution. https://mylodocs.com. Takes markdown files hosted in github and creates a beautiful documentation site.

https://docusaurus.io

Pretty big fan of gitbook. It's for books but can used for for docs or changelogs just the same

VuePress is a nice option the lets you write Markdown and then kicks out a static site: https://vuepress.vuejs.org/

RAML is fantastic for REST API documentation. Basically it's, higher level and less repetitive than Swagger.

For programs, I like inline docs that includes doctests (forcing them to stay in sync with the code). For something extensive, try Gitbook.

https://readme.io/

readthedocks.org is clean and nice. Check this https://solidity.readthedocs.io/en/latest/

Depends on what kind of documentation. I use react styleguidist for frontend components, docsify for general documentation. Both very clean, simple and straightforward, if they fit your project. For APIs I would use some other specialized API documentation tool.