Zcode

A simple and native code editor for Gnome built in Zig.

About

Zcode is a small, fast code editor for the Gnome desktop, written in Zig on top of GTK 4, libadwaita, GtkSourceView 5 and VTE, with a thin C layer for the GObject-heavy bits that don't translate cleanly to Zig. It aims to stay simple and native: one well-built editor pane, a collapsible project sidebar, an integrated terminal and language-server features, all following the Gnome Human Interface Guidelines.

Features

• Syntax highlighting — tree-sitter for Zig, Go, Rust, C, Python, JavaScript, TypeScript, TSX and Markdown, with incremental parsing and viewport-limited tagging for large files; GtkSourceView's native highlighter covers everything else.
• Language servers — LSP-backed completion, hover, go-to-definition, signature help, diagnostics, document formatting and code actions. Servers are spawned lazily per project and language (zls, gopls, rust-analyzer, clangd, pyright, typescript-language-server).
• Editor — find & replace (case, word, regex), quick open (Ctrl+P) with subsequence matching, go-to-line, configurable indentation, line numbers, word wrap and right-margin guide.
• Git integration — change bars in the gutter vs HEAD, added/removed line counts in the status bar, branch switching from the sidebar header.
• Integrated terminal — VTE with multiple tabs, following the system light/dark style.
• Markdown & HTML preview — live preview pane via WebKitGTK and cmark, with in-editor link handling.
• Image viewing — PNG, JPEG, SVG and other image formats open directly in a tab.

Screenshots

Dark	Light

Build

Zcode is Flatpak-first. A local binary build is useful for development and debugging.

Flatpak

1. Install flatpak and flatpak-builder (or the org.flatpak.Builder Flatpak app).

2. Run the build script:

   ./scripts/build-flatpak.sh --install --run

   This pulls the GNOME runtime/SDK from Flathub, builds the bundled dependencies (cmark, VTE, the Zig toolchain) and Zcode itself, installs it and runs it. Use --bundle to export a single-file .flatpak bundle instead.

Local binary (debugging)

Zcode links against GTK 4, libadwaita, GtkSourceView 5, VTE, WebKitGTK 6 and libcmark. On Fedora, install the development headers first:

sudo dnf install gtk4-devel libadwaita-devel gtksourceview5-devel \
                 vte291-gtk4-devel webkitgtk6.0-devel cmark-devel

libadwaita 1.8 or newer is required (AdwShortcutsDialog). Distributions still on 1.5, Ubuntu 24.04 among them, fail to link with a list of undefined adw_* symbols; build the Flatpak there instead, since its GNOME 50 runtime carries a new enough libadwaita.

Then build and run with Zig 0.16:

zig build run

The run step sets GSETTINGS_SCHEMA_DIR so preferences persist without a system-installed schema. A plain zig-out/bin/zcode without that variable runs without persistence instead of aborting.

Run the tests:

zig build test

Contributing

Contributions are welcome, see CONTRIBUTING.md for the rules that keep the project simple and maintainable, and how to report bugs.

Sandbox

Zcode's Flatpak deliberately runs with a wide sandbox, because the features below only work outside it:

Permission	Why
--talk-name=org.freedesktop.Flatpak	The integrated terminal and language servers run on the host, not in the sandbox — otherwise your shell, your PATH and your toolchains wouldn't be there.
--filesystem=home	Open and edit projects anywhere under $HOME.
--share=network	Language servers that fetch indexes, and remote images in the Markdown preview.

In practice this means Zcode can run commands on your host, like any editor with a built-in terminal. Previews are read-only by design: JavaScript is disabled for every previewed file, HTML included.

License

Zcode is released under the MIT License.

Bundled third-party components (tree-sitter and its grammars, the Catppuccin icon set, cmark and VTE in the Flatpak) keep their own permissive licences — see THIRD-PARTY.md.