It may seem hard to believe, but the RFC for ESLint’s new configuration system, nicknamed flat config, was first written in 2019. It took until 2022 (v8.21.0) for us to release an experimental, opt-in version of flat config. Since then, we’ve been making changes and improvements based on feedback from the community. The plan was always to allow the current configuration system, nicknamed eslintrc,
![Flat config rollout plans - ESLint - Pluggable JavaScript Linter](https://cdn-ak-scissors.b.st-hatena.com/image/square/4f93de79fc0479afbda73fa0f2f9dcff97396275/height=288;version=1;width=512/https%3A%2F%2Feslint.org%2Ficon-512.png)