orCAL

A small desktop calculator for Colony, with a phone keypad and a scientific tablet layout.

Every desktop ships a calculator, and each one looks, rounds and behaves its own way. orCAL is one calculator for Linux, Windows and macOS: it opens on a phone keypad for everyday sums, switches to a scientific keypad in one click, and sends every expression from either layout to the same Rust engine, so 0.1+0.2 is 0.3 on every system. It wears the Colony themes, fonts and accessibility settings, and it contains no network code.

Status: every release from v0.2.2 on is signed and published for the four targets below. CI checks formatting and lints, builds, runs --version and runs the tests on Linux, Windows and macOS, and builds on the Rust 1.90 floor. The tests cover the engine (operators, precedence, rounding, the scientific functions, every error), the preferences file, the folder layout, the migration from older versions, the window position and the English and French strings. The interface itself, both keypads and the Preferences page, has no automated test, and the macOS and Windows builds have not been tried by hand: there they are only proven to build, answer --version and pass the tests.

Why orCAL

• The same results everywhere. One engine in src/engine.rs evaluates both layouts on all three systems; the interface never evaluates code itself.
• Two calculators in one window. The phone layout is for quick sums; the tablet layout adds functions, powers, parentheses and the previous answer. The window controls in the status bar switch between them.
• It looks like the rest of Colony. Every Colony theme, an accent colour, the text size, high contrast, the OpenDyslexic font and reduced motion, in English or French.
• Nothing leaves the machine. No network code, no telemetry, no account, and releases that Colony checks against the organisation's signature before it installs them.

What it does

• Phone layout: +, -, ×, ÷, %, ±, decimals, backspace and clear. No parentheses there.
• Tablet layout (scientific): everything above, plus parentheses, sin, cos and tan in degrees, ln, log (base 10), square root, x², powers (xʸ, right associative), 1/x, factorials (!, whole numbers from 0 to 170), the constants π and e, and ANS for the previous result.
• Implicit multiplication: 2π, 2(3) and (2)(3) multiply.
• Rounding that does what you expect: results are rounded to 12 significant digits (whole parts are never cut), and sums and differences to the 15 digits an f64 keeps, so 0.1+0.2 gives 0.3, 0.1+0.2-0.3 gives 0 and 1/8 gives 0.125.
• Percent: % divides the number before it by 100 at full precision, so 200*0.5% gives 1.
• Clear errors: incomplete expression, invalid token, division by zero, undefined or infinite result, factorial out of range, and expressions nested more than 256 levels deep.
• Keyboard: digits, + - * /, %, . or , for the decimal point, Enter for =, Backspace, and Delete or Escape to clear, in both layouts.
• Preferences, opened and closed by clicking the orCAL name at the top left of the window, and saved as soon as they change:
  • General: English or French (or the system language), and the layout orCAL opens in.
  • Appearance: every Colony theme, an accent colour, the text size and animations, with a live preview.
  • Accessibility: high contrast, the OpenDyslexic font, reduced motion (also on when the system asks for it) and a reading text size that multiplies with the Appearance one.
  • About: the version, the licence and the folders orCAL uses on this machine.
• French number format: in French, results and the decimal key use a decimal comma.

Installation

Via Colony (recommended)

Install Colony, open the Utilities category and install orCAL. Updates arrive through the launcher, and Colony verifies each release's signature before it installs it.

Direct binary download

Grab the asset for your platform from the latest release. Each one ships with a matching .sig, .meta and .meta.sig.

Platform	Asset
Linux (x86_64)	orcal-linux
Windows (x86_64)	orcal-windows.exe
macOS (Apple Silicon)	orcal-macos
macOS (Intel)	orcal-macos-x86

There is no installer: download the asset and run it.

chmod +x orcal-linux && ./orcal-linux

--version prints the version and exits without opening a window. Releases up to v0.3.1 predate the flag: they ignore it and open the calculator.

orCAL draws its window with the system web view, so each platform needs it installed:

• Linux: WebKitGTK 4.1, with libsoup 3 and JavaScriptCore 4.1, which it pulls in (libwebkit2gtk-4.1-0 on Debian and Ubuntu, webkit2gtk-4.1 on Arch, webkit2gtk4.1 on Fedora). The binary is built on GitHub's ubuntu-latest runner and needs that runner's glibc, 2.39 today: Ubuntu 24.04, Debian 13, Fedora 40 or newer.
• Windows: the Microsoft Edge WebView2 Runtime. Windows 11 includes it; on Windows 10, install it from Microsoft if it is missing.
• macOS: nothing extra; WebKit is part of the system.

Build from source

git clone https://github.com/Project-Colony/orCAL
cd orCAL
cargo build --release

Requires Rust 1.90 or newer. On Debian and Ubuntu you also need libwebkit2gtk-4.1-dev; other systems need the equivalent WebKitGTK 4.1 development package on Linux, or the platform toolchain Tauri lists in its prerequisites. The binary is target/release/orCAL (orCAL.exe on Windows). cargo run builds and starts it in one step.

Documentation

orCAL is small enough to need no docs/ folder: this page is the user guide, and the notes below are for anyone reading or changing the code.

cargo test runs the engine, preferences, folder layout, migration, window position and command-line tests, and the checks that keep the English and French strings complete.

• src/main.rs: entry point, --version and the Tauri setup
• src/engine.rs: parsing and evaluation
• src/commands.rs: the commands the interface calls to evaluate an expression and to fill the About page
• src/preferences.rs: preferences.json and the commands that read and write it
• src/paths.rs: the Colony folder layout
• src/window_state.rs: opens the main window on the chosen layout and remembers its position between runs
• src/migrate.rs: copies the settings of versions before the Colony layout and opens the preferences store
• src/linux_display.rs: turns off WebKitGTK's DMA-BUF renderer and accelerated compositing under Wayland, where they fail on some drivers
• src/i18n.rs: tests that hold the two locale files to the same keys
• src/ui/: the HTML/CSS/JS interface, index.html for the phone layout and tablet-mode/ for the tablet one
• src/ui/common/: what both layouts share: the theme tokens and fonts (base.css), the window chrome, the Preferences page, and the preferences and translation layers
• src/ui/i18n/: orCAL's own interface strings, en.json (canonical) and fr.json
• src/ui/fonts/: JetBrains Mono Nerd Font and OpenDyslexic, each with its licence
• src/ui/vendor/colony/: the Colony theme data, with the strings every Colony program shares (Preferences, theme and accent names), refreshed with scripts/sync-colony-tokens.sh <commit> and never edited by hand
• tauri.conf.json: window, content security policy and capability settings
• assets/icons/: application icons

Code signing policy

Every release asset from v0.2.2 on is signed by the Project Colony organisation in CI, never on a developer machine; older releases predate signing. Next to each asset on the release page:

File	What it is
<asset>.sig	an ed25519 signature over the asset, made with the organisation's release key
<asset>.meta	three lines binding the asset to its file name, its sha256 and the release version
<asset>.meta.sig	an ed25519 signature over the .meta

The private key is an organisation secret, used only by the shared sign-and-publish workflow in a job that builds nothing; the jobs that compile orCAL never see it. Colony checks all three files before it installs or updates orCAL, and refuses a release older than the one installed. To check a download yourself with OpenSSL 3 (the same commands work for every asset):

cat > colony-release.pub <<'EOF'
-----BEGIN PUBLIC KEY-----
MCowBQYDK2VwAyEARNjg3Nn8H6/aBg1unwGjkUTcrdTxERNefVaqU8cFu0s=
-----END PUBLIC KEY-----
EOF
a=orcal-linux
openssl pkeyutl -verify -pubin -inkey colony-release.pub -rawin -in "$a" -sigfile "$a.sig"
openssl pkeyutl -verify -pubin -inkey colony-release.pub -rawin -in "$a.meta" -sigfile "$a.meta.sig"
cat "$a.meta"     # version=<tag>, asset=<file name>, sha256=<digest>
sha256sum "$a"    # the digest must equal the sha256 line

How releases are built, signed and published: design/releases.md.

Privacy

This program will not transfer any information to other networked systems unless specifically requested by the user or the person installing or operating it.

orCAL contains no network code and sends no telemetry, no analytics and no crash reports. It has no account and no update check; Colony handles updates. What it keeps stays on this machine, under Colony/orCAL/ in the local (never roaming) application folders:

Data	Stored or sent	Where, and why
Preferences	stored	preferences/preferences.json in the settings folder: theme, accent, text size, accessibility, language and startup layout, saved as soon as they change. A setting with a bad value falls back to its default; a theme orCAL does not ship becomes Gruvbox dark, Colony's fallback, and an unknown accent becomes the theme's own. A file that orCAL reads but that is not a JSON object is moved to preferences.json.bak and orCAL starts from the defaults. A file it cannot read (permissions, a lock) or cannot move aside is left untouched: orCAL starts from the defaults and saves nothing over it until the next launch
Window position	stored	window-position.json in the settings folder, so the window opens where you left it. On Wayland the compositor decides where windows open
Migration marker	stored	.migrated in the settings folder, written by the first launch of a version with the Colony layout. It records where the settings of older versions were looked for, so the copy below runs only once
Web view profile	stored	the web view's own storage and cache. orCAL keeps nothing of its own there once the old theme below has been imported, so it is cache: webview/ in the cache folder on Linux and Windows. On macOS, where the web view cannot be given a folder, it uses a non-persistent store kept in memory instead of the system's WebKit folder
Expressions and results	neither	kept only in the open window, gone when you close it

Folder	Linux	Windows	macOS
Settings	~/.config/Colony/orCAL/	%LOCALAPPDATA%\Colony\orCAL\	~/Library/Application Support/Colony/orCAL/
Data (not used)	~/.local/share/Colony/orCAL/	%LOCALAPPDATA%\Colony\orCAL\	~/Library/Application Support/Colony/orCAL/
Cache	~/.cache/Colony/orCAL/	%LOCALAPPDATA%\Colony\orCAL\cache\	~/Library/Caches/Colony/orCAL/ (not used)

Preferences > About shows the exact folders on your machine.

Versions before the Colony layout kept these in com.orcal.app folders. The first launch of a newer version copies the window position over and imports the theme from the old web view storage; the launch after that switches to the new web view profile. The old com.orcal.app folders are left in place and can be deleted by hand, and so can the webview/ folder that 0.4.0 kept in the data folder on Linux and Windows.

The interface is drawn by the operating system's web view (Microsoft Edge WebView2 on Windows, WebKit on macOS and Linux), which follows its vendor's own privacy policy.

License

GPL-3.0-or-later. You may redistribute and modify orCAL under the terms of version 3 of the GNU General Public License, or (at your option) any later version. The full text is in LICENSE.

The bundled fonts, JetBrains Mono Nerd Font and OpenDyslexic, are under the SIL Open Font License 1.1, whose text sits next to each of them in src/ui/fonts/.