KiwiDesk

Why it's ranked here

The project documents itself like a product with users to answer to. It publishes a measured performance page comparing releases on a fixed desk of windows, a page of accepted limitations that names each known bug's architectural cause and workaround, and an architecture guide for every pipeline. It also ships a built-in MCP (Model Context Protocol) server so AI apps can change layouts, with irreversible commands routed through a separate tool that asks first. The weight against it: the license is source-available rather than open source, and it runs only on Apple silicon Macs.

What's good

It skips the two usual costs of Mac tiling managers: System Integrity Protection stays on, and hotkeys use the older Carbon registration, so no Input Monitoring permission is needed. Lua config has guard rails. Any single call into the script engine is cut off after 500 ms, a failing callback is disabled instead of taking the app down, and a mistyped function name becomes a logged no-op with a did-you-mean hint. The command line lists every command with its legal values read from the code that parses them, so the help cannot drift from behaviour. It ships as a signed, notarized app that updates itself through Sparkle.

Tradeoffs

The Business Source License 1.1 allows free use at home and at work but forbids offering, selling, bundling or hosting it as a product without a commercial license. Each version turns MIT four years after publication, and versions before 1.3.0 stay MIT. It needs macOS 14 or later on Apple silicon, so Intel Macs are out. Switching macOS Desktops by number relies on an Apple bridge the docs confirm on only one macOS build. The limitations page lists several timing edge cases around Desktop switches, sticky windows and fullscreen apps. Under a saturated GPU, the slowest layout pass in its own benchmark reached 229 ms.

How to use it well

Best for someone on an Apple silicon Mac who wants tiling without writing a config file first. Install through Homebrew to get the command line on your path, grant Accessibility, and start from the Settings app. Reach for Lua only for event hooks or custom behaviour, and know that declaring any setting in the Lua file hands ownership away from the Settings app. Status-bar users get ready recipes for SketchyBar and JankyBorders. If you plan to resell or bundle a window manager, or run an Intel Mac, look elsewhere.

Observed

License

Business Source License 1.1; each version converts to MIT four years after publication (LICENSE)

Language

Swift 6, with vendored Lua 5.5 C sources

Platform

macOS 14 or later, Apple silicon only

Install

Homebrew cask or signed, notarized disk image; Sparkle in-app updates

Interfaces

Settings GUI, CLI over a UNIX socket, Lua config, MCP server

Permissions

Accessibility only; System Integrity Protection stays enabled

Tests

Two Swift test targets (Core and GUI) declared in Package.swift