Alternatives to Lem
A general-purpose editor and IDE written in and extensible with Common Lisp, with Emacs and Vim keybindings. The listings below can replace it for an important use case. Each note says what changes if you switch.
The original
Lem
A general-purpose editor and IDE written in and extensible with Common Lisp, with Emacs and Vim keybindings.
Replacements
Listings that take over the same core job as Lem.
GNU Emacs
An editor that is really a Lisp environment, extensible to the point where people run their email, calendar and shell inside it.
GNU Emacs is extended in Emacs Lisp instead of Common Lisp, adds Org mode and decades of stable configurations, and has Windows builds, but its Lisp is single-threaded.
Doom Emacs
An opinionated configuration framework that turns GNU Emacs into a fast, modular editing environment.
Doom Emacs gives a modular, ready-made GNU Emacs setup with an active community, configured in Emacs Lisp, and requires Emacs to be installed first.
Spacemacs
A community-driven Emacs configuration that combines Emacs with Vim-style editing and mnemonic key bindings.
Spacemacs combines Emacs packages with Vim-style editing and mnemonic key bindings through curated layers, though its large configuration can slow startup.
Neovim
A modern rewrite of Vim with a built-in language server client, Lua configuration and an embeddable API.
Neovim offers Vim-style modal editing with a built-in LSP client and Lua configuration, and runs on Windows too, but has no Emacs-like mode or Lisp REPL.
Vim
The editor that is already on every server, with a graphical build for Windows and a licence that asks you to donate to Ugandan children.
Vim provides modal editing already installed on nearly every server and configured in Vimscript, but language server support needs plugins and there is no Lisp REPL.
Helix
A modal terminal editor with language servers and multiple selections built in, and no plugins to install.
Helix is a terminal modal editor with language servers built in and no configuration project, but it has no plugin system, so it cannot be extended like Lem.
Also worth comparing
These listings name Lem as their own alternative, so the relationship runs both ways.
Aquamacs
An editor based on GNU Emacs and adapted to feel at home on macOS.
Lem is an open-source editor extensible in Common Lisp with Emacs-like and Vim-like modes on macOS and Linux, so Emacs Lisp packages and configuration do not carry over.
Kakoune
A modal terminal code editor where multiple selections are the main way of editing.
Lem offers Emacs-like and Vim-like modes with built-in LSP support and is extensible in Common Lisp, though its GUI is moving from SDL2 to a webview.
Similar software
Related functionality, not a direct replacement.
Magit
A complete text-based Git interface that runs inside GNU Emacs.
Denote
An Emacs note-taking package that organises plain-text notes through a predictable, descriptive file naming scheme.
Neovide
A cross-platform graphical interface for Neovim that adds smooth animations and other visual improvements.
