Here are some other solutions that are free, open source and under active development.
- Grav (https://getgrav.org/) (PHP)
- Bolt (https://bolt.cm/) (PHP)
- Pico (http://picocms.org/) (PHP)
- Hugo (https://gohugo.io/) (Go)
- Astro (https://astro.build/) (Node.js + any framework)
- VitePress (https://vitepress.vuejs.org/) (Vue.js)
- Gridsome (https://gridsome.org/) (Vue.js)
- Hexo (https://hexo.io/) (Node.js)
- Jekyll (https://jekyllrb.com/) (Ruby)
- Pelican (http://getpelican.com/) (Python)
- Metalsmith (http://www.metalsmith.io/) (Node.js)
- Gatsby (https://github.com/gatsbyjs/gatsby) (React)
- MkDocs (http://www.mkdocs.org/) (Python)
- Hakyll (https://jaspervdj.be/hakyll/) (Haskell)
- Lektor (https://www.getlektor.com/) (Python)
- Bi Sheng (https://github.com/benjycui/bisheng) (Node.js)
- Nuxt (https://nuxtjs.org/) (Vue.js, via
nuxt generatecommand) - Next.js (https://nextjs.org/) (React, via
next exportcommand) - Docusaurus (https://docusaurus.io/) (React)
- Nextein (https://nextein.now.sh/) (React, Next.js)
- Eleventy (https://www.11ty.io/)
- Netlify CMS (https://www.netlifycms.org/) (React)
- Forestry (https://forestry.io/) (Jekyll, Hugo, Git)
- Vercel
- Netlify
- Cloudflare Pages
- Surge
- render
- fly.io
- Railway
- DigitalOcean App Platform
- GitHub Pages
- Koyeb
- Firebase Hosting
- Google App Engine
- Azure Static Web Apps
- October (https://octobercms.com/) (PHP)
- Sulu (http://sulu.io/) (PHP)
- Roadiz (https://www.roadiz.io/) (PHP)
- KeystoneJS (http://keystonejs.com/) (Node.js + MongoDB)
- Apostrophe (http://apostrophenow.org/) (Node.js + MongoDB)
- Concrete5 (https://www.concrete5.org/) (PHP)
- Postleaf (https://www.postleaf.org/) (PHP)
- Neos (https://www.neos.io/) (PHP)
- Redaxscript (https://redaxscript.com/) (PHP)