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 generate command)
• Next.js (https://nextjs.org/) (React, via next export command)
• 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)