Vrite - Open-source, headless CMS for technical content.
ReadTheDocs - Spend your time on writing high quality documentation, not on the tools to make your documentation work.
Ahrefs - Ahrefs is a toolset for SEO and marketing. We have tools for backlink research, organic traffic research, keyword research, content marketing & more. Give Ahrefs a try!
Docsie - Docsie makes it easy to create and maintain your website documentation, without having to deploy it...
Doclets.io - Simple automated and hosted API-Doc for JSDoc / Javascript
ReadMe - A collaborative developer hub for your API or code.