Ary Borenszweig, Juan Wajnerman, and Brian Cardiff created the Crystal programming language.
Crystal is a compiled, statically typed language whose syntax is heavily inspired by Ruby. The creators aimed to combine Ruby-like expressiveness with the performance and predictable deployment associated with compiled native programs.
Crystal uses type inference, so many programs can avoid explicit type annotations while still receiving compile-time type checking. Its compiler generates native code through LLVM, and the language includes concurrency features based on lightweight fibers and channels.
Crystal is not Ruby, despite their similar syntax. Ruby is generally interpreted or executed through virtual machines, while Crystal compiles ahead of execution into native binaries. The resemblance is intentional: Ruby developers can often recognize Crystal's syntax, but the languages have different runtimes, libraries, and compatibility guarantees.