CoffeeScript

CoffeeScript is a small programming language that compiles directly into JavaScript, designed to expose JavaScript's core features in a simpler syntax while following the rule that it is just JavaScript. Code compiles one-to-one into equivalent JavaScript with no runtime interpretation, producing readable, pretty-printed output that can interoperate with existing JavaScript libraries in either direction. The current version is 2.7.0.

CoffeeScript 2 emits modern JavaScript syntax (ES2015 and later), including arrow functions, classes, async functions, and JSX. The coffee command-line utility can execute scripts, compile .coffee files to .js, run an interactive REPL, watch files for changes, generate source maps, and optionally pipe output through Babel for transpilation. The core compiler does not depend on Node and can run in any JavaScript environment or the browser. Additional commands include cake, and options exist for literate CoffeeScript, AST generation, and token output.

CoffeeScript is intended for developers writing JavaScript applications who prefer a more concise syntax. It is installed via npm as a local project dependency or globally, and is distributed as open-source software with no paid editions or usage-based pricing.