GALA

GALA (Go Alternative LAnguage) is a programming language that compiles to Go source code, bringing functional features Go lacks: sealed types, exhaustive pattern matching, Option/Either/Try monads, and immutable-by-default values. It targets Go developers familiar with Scala, Kotlin, F#, or OCaml who want those language features while keeping full access to the Go ecosystem and third-party modules.

The language prioritizes safety by catching runtime bugs at compile time—incomplete pattern matches fail to build, nil is replaced with proper Option types, and data races are detected before execution. It includes a standard library with immutable collections (List, HashMap, TreeSet, etc.) and functional operations. The maker says it was built with Claude Code.