Gleam

Gleam is a statically typed functional programming language designed for building type-safe, scalable systems, originally created by Louis Pilfold in 2018 and running on the Erlang Virtual Machine (BEAM). With over 18,000 stars as of 2026, Gleam combines the safety of a strong static type system with the concurrency and fault-tolerance of the Erlang/OTP ecosystem, making it suitable for building reliable distributed systems, web servers, and real-time applications. Key features include: strong static type system with full type inference (no type annotations needed in most cases), algebraic data types (custom types with variants, enabling expressive modeling of domain logic), exhaustive pattern matching (the compiler ensures all cases are handled), no null values (using Result type for error handling and Option type for optional values), immutable data structures by default, Erlang/OTP actor model concurrency (lightweight processes communicating via message passing, with supervision trees for fault tolerance), JavaScript compilation target (in addition to Erlang, enabling web frontend development), friendly error messages with source locations and suggestions, a formatter (gleam format) for consistent code style, a build tool (gleam build) with dependency management via hex.pm package registry, FFI (Foreign Function Interface) for calling Erlang and JavaScript functions, labeled arguments for improved readability, use expressions for resource management (similar to RAII or Python context managers), and a growing ecosystem of packages.