On-the-fly syntax checking for GNU Emacs. Flycheck is a modern on-the-fly syntax checking extension for GNU Emacs, intended as replacement for the older Flymake extension which is part of GNU Emacs. Flycheck automatically checks buffers for errors while you type, and reports warnings and errors directly in the buffer and in an optional IDE-like error list. It comes with a rich interface for custom syntax checkers and other extensions, and has already many 3rd party extensions adding new features. Please read the online manual at https://www.flycheck.org for more information. You can open the manual directly from Emacs with `M-x flycheck-manual'. # Setup Flycheck works best on Unix systems. It does not officially support Windows, but tries to maintain Windows compatibility and should generally work fine on Windows, too. To enable Flycheck add the following to your init file: (add-hook 'after-init-hook #'global-flycheck-mode) Flycheck will then automatically check buffers in supported languages, as long as all necessary tools are present. Use `flycheck-verify-setup' to troubleshoot your Flycheck setup.