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Lem is the editor/IDE well-tuned for Common Lisp.

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After installing lem, you can start developing in Common Lisp at once.

In addition, many languages are supported with Lem’s built-in LSP support.

Getting Started

Feature overview

Keyboard oriented

If you come from Emacs or Vim, you will feel right at home.

Alien Technology

It is an established fact that John McCarthy shared alien tech with the world in 1958 when he introduced us to Lisp. We continue that great tradition.

Lem is written and extensible in Common Lisp.

GUI version using SDL2

Since version 2.0, a GUI version is also available.

It brings graphics and mouse support, as well as games and over 180 colour themes.

Ready for Common Lisp

Start developing on Lisp at once.

Full-featured REPL and interactive debugger, with Paredit and a third-party Pareto (lispy-mode) mode.

Project tree view

Open a tree view of the current project,

use project-aware commands.

and more

File tree on the left.

Multiple cursors, interactive grep, directory mode, tabs, Git interface,

and support for:

Scheme, Go, JavaScript, TypeScript, Python, Rust, Elixir, Haskell, Java, Nim, Dart, OCaml, Scala, Swift, shell, asm

markdown, ascii, JSON, HTML and CSS, SQL…