.ex File — Elixir Source Code

Elixir is a dynamic, functional programming language created by José Valim in 2011 that runs on the Erlang Virtual Machine (BEAM). EX files contain compiled Elixir source code (as opposed to .exs for scripts) in a language designed for building scalable, maintainable, and fault-tolerant distributed systems. Elixir leverages the BEAM's battle-tested concurrency model — lightweight processes, message passing, supervision trees, and hot code reloading — capabilities refined over decades in Erlang for telecom systems. The language features pattern matching, pipe operators for data transformation chains, protocols for polymorphism, macros for metaprogramming, and comprehensions. The Phoenix web framework brings Rails-like productivity with real-time capabilities through Phoenix Channels (WebSocket), Phoenix LiveView (server-rendered interactive UIs without JavaScript), and excellent performance. Elixir's OTP (Open Telecom Platform) patterns including GenServer, Supervisor, and Application provide battle-tested architectures for fault-tolerant systems. The language is used by companies like Discord, Pinterest, PepsiCo, and Bleacher Report for high-concurrency services. Mix is the build tool and Hex is the package manager for the growing ecosystem.