// the find
defunkt/coffee-mode
Emacs Major Mode for CoffeeScript
An Emacs major mode for CoffeeScript, giving you syntax highlighting, indentation, imenu navigation, and REPL/compile integration inside Emacs. It's for the shrinking pool of developers still maintaining CoffeeScript codebases in Emacs, not for anyone starting new work in the language.
Covers the basics well: indentation is configurable per-buffer via file-local variables, imenu support means textmate.el-style symbol jumping works out of the box, and it has a real test suite (coffee-command, coffee-highlight, coffee-imenu, coffee-syntax) running in CI rather than just a bare .el file. The sourcemap hook for jumping from compiled JS back to the original CoffeeScript source is a genuinely useful detail most language modes skip.
Last push was September 2023 — CoffeeScript adoption has been flat-to-declining for years, so this is maintenance mode, not active development. Compile and REPL commands shell out to the external coffee binary, so half the mode's functionality does nothing until you have Node and the right CoffeeScript version installed separately. No LSP/eglot integration, so you get syntax highlighting and indentation but none of the completion or diagnostics you'd expect from a modern major mode. If you're not already stuck maintaining legacy CoffeeScript, there's no reason to reach for this.