Open Source CMS
Content outlives the platform that publishes it, so the real choice in a CMS is how cleanly your articles and structure come back out when you migrate, not how the dashboard looks today. The open source options here store content in databases and formats you can export in full, run on hosting you pick, and separate what you wrote from how it's rendered, so moving to the next system doesn't mean rewriting your archive.
Strapi
Model content visually and Strapi generates REST and GraphQL APIs with a self-hosted admin
Ghost
Open source publishing platform with built-in newsletters, memberships, and paid subscriptions
Payload
A Next.js native headless CMS that installs in your app folder with a TypeScript backend
Directus
Wraps any SQL database in instant REST and GraphQL APIs, a no-code admin app, and auth
GrapesJS
Free and open source web builder framework for creating HTML templates inside CMS and other apps
WordPress
Open source CMS for creating a self-hosted website, blog, or app with a plugin API
Wagtail
Open source Django CMS with flexible content modeling, integrated search, and headless delivery
TinyMCE
Open source JavaScript WYSIWYG rich text editor with React, Vue, and Angular integrations
Grav
Flat-file CMS for building and managing websites with zero installation