At its core is an interpreter for Emacs Lisp, a dialect of the Lisp programming language with extensions to support text editing.
* Content-aware editing modes, including syntax coloring, for many file types.
* Complete built-in documentation, including a tutorial for new users.
* Full Unicode support for nearly all human scripts.
* Highly customizable, using Emacs Lisp code or a graphical interface.
* An entire ecosystem of functionality beyond text editing, including a project planner, mail and news reader, debugger interface, calendar, and more.
* A packaging system for downloading and installing extensions.