Appendix B: The Future of Crystal
Crystal has recently graduated as stable and production-ready with the release of version 1.0.0 in March 2021. As of April 2022, the latest version is 1.4.1, which has many refinements. Still, there is much work ahead, and many areas of the language will see improvement in further releases. All development and design discussions happen in the open in the official GitHub repository, and there is plenty of opportunity for contribution from outsiders.
Today, Crystal is already used by several companies in production. You can find a public list of some of those on Crystal's Wiki here: https://github.com/crystal-lang/crystal/wiki/Used-in-production. Adoption is expected to rise even further now that there is a proper policy of no breaking changes being introduced. Source code built now will compile fine with no changes on all future 1.x versions.