Colomin

A fast, native CSV editor for macOS, Linux, and Windows, built with Rust and eframe/egui.

Focuses on fast file open/save, spreadsheet-style editing, and file-manager–friendly app behavior without a web stack.

Features

• Open CSV, TSV, and delimited text files
• Auto-detect common delimiters: comma, semicolon, tab, pipe
• Column type inference on load
• Background indexing with visible loading progress
• Spreadsheet-style cell, row, and column selection
• In-place cell editing with undo/redo
• Copy/paste rectangular cell ranges
• Column sorting
• Insert/delete/reorder rows and columns, plus column rename
• Selection stats for count, sum, avg, min, max, and character length
• Multiple bundled light/dark themes
• Font, font-size, and zoom controls
• Drag-and-drop file opening
• File-manager "Open With" integration on every platform (Finder on macOS, Explorer on Windows, GNOME Files / Dolphin / Thunar on Linux via .desktop MimeType associations)
• Tab mode or separate-window instance mode (single-instance handoff via Unix sockets on macOS/Linux, named pipes on Windows)
• Optional session debug logging

Run

Requires a Rust toolchain.

# Development (empty window)
cargo run

# Development with a file
cargo run -- /path/to/file.csv

Build

# Release binary
cargo build --release

# All platform packages
cargo install cargo-packager cargo-generate-rpm --locked
cargo packager --release
cargo generate-rpm     # Linux only — produces a .rpm

Artifacts (per OS, written to dist/ and target/generate-rpm/):

Platform	Outputs
macOS	Colomin.app, Colomin*.dmg (universal: arm64 + x86_64)
Linux	colomin*.deb, Colomin*.AppImage, colomin*.rpm (per arch: x86_64 + arm64)
Windows	Colomin*.msi (x86_64 only — WiX 3.x doesn't reliably emit arm64), portable colomin.exe

CI does this automatically for every v* tag — see .github/workflows/release.yml.

macOS releases fail unless these GitHub Actions secrets are set:

Secret	Placeholder / expected value
MACOS_SIGNING_IDENTITY	Developer ID Application: YOUR_NAME_OR_ORG (TEAMID)
MACOS_CERTIFICATE	Base64-encoded Developer ID Application .p12 certificate
MACOS_CERTIFICATE_PWD	Password used when exporting the .p12
AC_API_KEY_P8	App Store Connect API key .p8 contents
AC_API_KEY_ID	App Store Connect API key ID
AC_API_KEY_ISSUER_ID	App Store Connect issuer ID

For quick local iteration on macOS:

cargo packager --release --formats app
ln -sf "$(pwd)/dist/Colomin.app" /Applications/Colomin.app
open /Applications/Colomin.app --args /tmp/wide_test.csv

Install

Download the latest release from the Releases page. All assets are version-pinned; releases/latest always serves the newest.

macOS (Apple Silicon + Intel, signed + notarized)

• Download Colomin.dmg, open it, drag Colomin.app to Applications.
• First launch opens normally — no Gatekeeper warning, since the build is notarized by Apple.

Linux (x86_64 + arm64)

• .deb (Debian, Ubuntu, Pop!_OS, Mint): sudo dpkg -i Colomin*.deb or open in your distro's App Center.
• .rpm (Fedora, RHEL, openSUSE, Rocky): sudo dnf install ./Colomin*.rpm (or rpm -i).
• .AppImage (any glibc Linux — Arch, NixOS, etc.): chmod +x Colomin*.AppImage && ./Colomin*.AppImage.
• All three install/register Colomin as a .csv/.tsv handler.
• Expected: GNOME Software / Discover / App Center will show "Unknown publisher" — this is the universal third-party .deb/.rpm experience and doesn't block install. Same as Slack, Discord, 1Password.

Windows (x86_64 native, arm64 portable)

• x86_64 (most PCs): download Colomin.msi, double-click, run the installer wizard. Registers .csv file associations + Start Menu entry.
• arm64 (Snapdragon X PCs, Surface Pro X): download Colomin-portable-arm64.zip, extract colomin.exe, run from anywhere. The binary is fully native arm64 — no emulation. A signed arm64 MSI is pending cargo-packager's upgrade to WiX 4.
• Also available: Colomin-portable-x86_64.zip for users who prefer not to install.
• Expected: SmartScreen will show "Windows protected your PC / Unknown publisher" — click More info → Run anyway. The binary is unsigned (Windows code-signing certs aren't free); same as most open-source Windows apps.

Platform behavior

• File-association "Open With" routes through native APIs on each platform — Apple Events on macOS, file-association registry entries on Windows, MIME type handlers on Linux. Existing instance reuse works on all three.
• Tab mode opens additional files as new tabs in the running app. Instance mode spawns a fresh process per file.
• Single-instance handoff uses a per-user Unix socket on macOS/Linux (/tmp/colomin-$USER.sock) and a named pipe on Windows (\\.\pipe\colomin-%USERNAME%).
• Icons + document associations are generated by cargo-packager from [package.metadata.packager] in Cargo.toml (+ [package.metadata.generate-rpm] for RPM). Linux also ships an AppStream metainfo file at /usr/share/metainfo/com.colomin.app.metainfo.xml so the pre-install view in App Center shows the app name, icon, and description.

Keyboard shortcuts

Cmd on macOS, Ctrl on Windows/Linux. The bindings are otherwise identical across platforms.

Shortcut	Action
Cmd/Ctrl+O	Open file
Cmd/Ctrl+S	Save current file
Cmd/Ctrl+W	Close current tab
Cmd/Ctrl+T	New tab
Cmd/Ctrl+Shift+T	Cycle theme
Cmd/Ctrl+F	Find in table
Cmd/Ctrl+= / Cmd/Ctrl+- / Cmd/Ctrl+0	Zoom in / out / reset
Cmd/Ctrl+C	Copy selection
Cmd/Ctrl+V	Paste into cell selection
Cmd/Ctrl+Z	Undo
Cmd/Ctrl+Shift+Z or Cmd/Ctrl+Y	Redo
Arrow keys	Move cell selection
Shift+Arrow	Extend selection
Enter	Edit selected cell
Escape	Clear selection
Delete / Backspace	Clear selected cells

Configuration and logs

Per-platform standard locations (Colomin uses the dirs crate to resolve them):

Path	macOS	Linux	Windows
Settings	~/.config/colomin/settings.json	~/.config/colomin/settings.json	%APPDATA%\colomin\settings.json
Debug logs (when enabled)	~/Library/Logs/Colomin/	$XDG_STATE_HOME/colomin/ or ~/.local/state/colomin/	%LOCALAPPDATA%\colomin\logs\
Panic log	$TMPDIR/colomin_panic.log	/tmp/colomin_panic.log	%TEMP%\colomin_panic.log

Notes

• Themes are bundled from themes/*.tokens.json
• Icons are embedded from assets/icons/*.svg
• The UI stack is eframe/egui — glow/OpenGL backend on macOS + Linux, wgpu/DirectX 12 backend on Windows (avoids OpenGL driver issues on Windows servers and VMs)

Provenance

Significant portions of this codebase were drafted with AI assistance and reviewed, tested, and integrated by a human maintainer.

Licensing

Colomin uses a dual model:

• Open source code under AGPL v3 (or later)
• Commercial terms for official business use of branded binaries/services

See:

• Commercial Terms
• Trademark and Branding Policy

This repository documentation is a practical policy draft, not legal advice.