GatsbyJS

GatsbyJS is a static site generator based on React. It is used to build static websites that are progressive web apps, follow the latest web standards, and are optimized to be highly performant.

GatsbyJs was a good alternative to NextJS, but we prefer NextJS as it's easier to integrate with our existing ReactJS applications: GatsbyJs philosophy of throwing GraphQL everywhere in the mix, makes things more complex than they could be.

Moreover, NextJS is more mature and has a larger active community while the open source community around GatsbyJS is not as active as it used to be and the project looks like it is not evolving as fast as NextJS. See https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby/CHANGELOG.md for the changelog of the GatsbyJS project.