A small, fast code editor, written in assembly

Why rhun

When coding agents do the heavy lifting, you don't need everything VS Code or Zed carries. You need to read and edit code, run commands, find files and see what changed. rhun does that, instantly.

Everything you need, nothing you don't

Every screenshot here is rhun running on Linux. On a Mac, Command works as Ctrl.

Editing that keeps up

Tabs, syntax highlighting, find and replace Ctrl H, find in files, word wrap and an optional Vim mode.

A terminal beside the code

Open a shell with Ctrl ` for builds, tests or a coding agent: 24-bit color, mouse and full-screen programs.

Git, built in

Changed lines in the gutter, diffs against HEAD, and every branch's history as a graph Ctrl Shift G.

Find anything

Go to File Ctrl P, the command palette Ctrl Shift P and find in files Ctrl Shift F, all fuzzy and instant.

Watch your agents work

The agents panel follows the project's Claude Code and Codex sessions live Ctrl Shift A.

Vim mode, if you want it

Normal, insert and visual modes, operators, text objects, counts, . and : commands. Off by default.

Settings you can read

A settings page and a plain config file, both applied while rhun runs.

Images in a tab

PNG, JPEG, GIF, BMP, ICO, QOI, PNM and TGA, with zoom and pan.

39 themes, dark and light

Switch with Ctrl Shift T, follow Omarchy, or write your own in three lines.

All built-in themes: Ayu Light, Catppuccin Latte, Catppuccin Mocha, Dracula, Elflord Dark, Elflord Light, Ethereal, Everforest, Flexoki Light, GitHub Dark, GitHub Light, Gruvbox Dark, Gruvbox Light, Hackerman, Kanagawa, Last Horizon, Lumon, Lupine, Matte Black, Miasma, Min Dark, Min Light, Monokai, Nord, One Dark, One Light, Osaka Jade, Retro 82, Rhun Dark, Rhun Light, Ristretto, Rosé Pine, Rosé Pine Dawn, Solarized Dark, Solarized Light, Solitude, Tokyo Night, Vantablack, White.

127 languages and file formats

Each grammar is a small text file; add your own in ~/.config/rhun/syntax/.

Built in: Ada, Apache, AppleScript, AsciiDoc, Assembly, Astro, AWK, Batch, BibTeX, Blade, C, C#, C++, Cap'n Proto, Clojure, CMake, COBOL, Crontab, Crystal, CSS, CUDA, CUE, D, Dart, Dhall, Diff, Dockerfile, dotenv, EJS, Elixir, Elm, ERB, Erlang, F#, Fish, Fortran, Git attributes, Git commit, Gleam, GLSL, Go, GraphQL, Graphviz, Groovy, HAML, Handlebars, Haskell, Haxe, HCL, HTML, HTTP, Idris, Ignore files, INI, Janet, Java, JavaScript, Jinja, JSON, Jsonnet, Julia, Just, KDL, Kotlin, LaTeX, Lean, Liquid, Lua, Makefile, Markdown, MATLAB, Mermaid, Meson, Mojo, Nginx, Nim, Ninja, Nix, Objective-C, OCaml, Odin, Org, Pascal, Perl, PHP, Pkl, PlantUML, PowerShell, Prisma, Prolog, Properties, Protocol Buffers, Pug, Puppet, PureScript, Python, R, Raku, Razor, Rego, reStructuredText, RON, Ruby, Rust, Scala, Shell, Slim, Solidity, SQL, SSH config, Starlark, Swift, Tcl, Thrift, TOML, Twig, TypeScript, Typst, V, Vala, Verilog, VHDL, Vim script, Visual Basic, XML, YAML and Zig.

Small on purpose

Written in x86-64 assembly. rhun draws every pixel itself and speaks Wayland, X11 or AppKit directly.

Install rhun

On Linux rhun goes to ~/.local with a desktop entry; on macOS to /Applications. Either way rhun starts it from a terminal. The installer checks SHA-256 checksums (and the signature on macOS). Uninstall with sh -s -- --uninstall. More in the guide.