Developers today often choose between open-source and cloud headless CMSs. Strapi combines the best of both. It's low-cost, customizable, and portable; it also has a great API, is scalable, and easy to set up.
I had zero Gatsby knowledge - within a day of reading their docs, I seamlessly integrated it with Strapi using the gatsby-source-strapi plugin. After providing my Strapi API URL and registering content-types, I was able to make an awesome personal website within a few days of work.
Nuxt.js is a free and open-source web application framework based on Vue.js, Node.js, Webpack, and Babel.js.
Next.js is a minimalistic framework for server-rendered React applications as well as statically exported React apps.