Many Displays

Product Introduction

1. Definition: Many Displays is a macOS menu bar utility application designed to automatically restore window positions and monitor arrangements. It operates as a background daemon that monitors the macOS window server and display state.
2. Core Value Proposition: It exists to solve the persistent macOS bug where windows are incorrectly piled onto a single monitor and identical displays are swapped after the system wakes from sleep, unlocks, or reconnects to a docking station. Its core value is zero-click, automatic window management that requires no manual layout saving, specifically engineered for multi-monitor setups with identical displays.

Main Features

1. Automatic, Event-Driven Restoration: The app restores window layouts automatically upon specific system events: wake from sleep, user unlock, login, or monitor reconnection. It requires no user-triggered shortcuts or saved layout files. It works by freezing its layout memory during system transition events (sleep/lock) and initiating a restore sequence once the display configuration is stable for a few seconds.
2. Hardware-Level Display Identification: A key technical feature is its ability to differentiate between identical monitors (which share a serial number). It uses a multi-tier identification system: first by the display's system UUID, then by the physical Thunderbolt/USB-C port it's connected to (on Apple Silicon Macs), and finally by screen position. This prevents the display swapping issue inherent to macOS.
3. Low-Level, Non-Blocking Window Tracking: Instead of using the slower Accessibility API to query each application, Many Displays reads the window list directly from the macOS window server (Core Graphics). This allows it to track hundreds of windows in approximately 20ms without being blocked by unresponsive applications, ensuring system performance and reliability.
4. Full Display State Restoration: Beyond windows, the app can also restore the physical display arrangement (which monitor is primary, left/right order), resolution, refresh rate, rotation, and HDR settings. This happens before windows are moved, ensuring a correct canvas for restoration.
5. Privacy-First & Offline Architecture: The application has no network access, analytics, or cloud components. Layout data is stored locally in a JSON file. The source code is available on GitHub under the Functional Source License, providing transparency into its operations.

Problems Solved

1. Pain Point: The core pain point is macOS window management failure after sleep/disconnect, a documented Apple bug reported since 2011 that Apple has stated behaves "as intended." This forces users to manually reorganize their workspace multiple times daily.
2. Target Audience: The primary user personas are professional multi-monitor Mac users: software developers, video editors, financial analysts, data scientists, and designers who use docked MacBooks or Mac desktops with multiple external displays, especially those using two or more identical monitor models.
3. Use Cases:
   • Docked MacBook Pro/Air Users: Closing the lid, undocking, and later re-docking to find all windows misplaced.
   • Mac Studio/Mini Users: Whose system goes to display sleep and upon wake, has all windows collapsed to one screen.
   • Users with Identical Monitors: Who experience left/right display swapping randomly after every sleep cycle.
   • Users with Complex Spaces/Desktops: Who need windows on multiple virtual desktops (Spaces) to be remembered and restored automatically.

Unique Advantages

1. Strengths & Limitations (Pros & Cons):

   • Pros:
     • Truly Hands-Free: The only solution that works 100% automatically without any user save/load action.
     • Superior Display Identification: Uniquely solves the identical monitor problem better than competitors.
     • High Performance: Low-overhead, non-blocking architecture using window server APIs.
     • Transparent & Private: Offline, open-source core, no subscriptions.
     • Restores Display Settings: Corrects macOS's arrangement/resolution mistakes.
   • Cons:
     • macOS Version Lock: Requires macOS 13 (Ventura) or later, excluding older systems.
     • Space (Virtual Desktop) Limitation: Due to macOS 14.5+ restrictions, it cannot move windows between Spaces unless SIP is disabled. It can only restore a window to its correct display within its current Space.
     • Requires Accessibility Permission: Like all window managers, it needs this permission, which may concern some enterprise security policies.

2. Key Alternatives & Differentiation:

   • Stay, Moom, Rectangle: These are primarily manual window snapping/tiling tools or require users to manually save and trigger named layouts. They do not offer automatic, event-driven restoration and fail to correctly identify identical monitors.
   • Display Maid, Putback: Closer in function, but often rely on the slower Accessibility API, can hang on unresponsive apps, and typically only trigger on display connection events, not on wake/unlock. They usually treat identical monitors as the same device.
   • Pricing & Model Differentiation: Many Displays uses a one-time purchase model ($19 for a year of updates + perpetual use of the last version) versus common subscription models or higher one-time fees in the category. Its workflow is fundamentally different: passive learning vs. active saving.

Frequently Asked Questions (FAQ)

1. Does Many Displays work with two identical Apple Studio Displays or Dell monitors? Yes, this is its primary design case. It uses the display's system UUID and physical connection port to tell them apart, preventing the swapping that native macOS causes.
2. Do I need to save a layout or press a shortcut for Many Displays to work? No. It operates automatically. It learns your window layout in the background (saving every ~1.5 seconds after a change) and restores it automatically after wake, unlock, or monitor reconnect with zero user interaction.
3. How does Many Displays affect MacBook battery life when used without external monitors? When no external displays are connected, the app enters a fully idle state with no active timers or observers, resulting in zero impact on battery life or system performance.
4. Can I use Many Displays alongside other window managers like Rectangle or Magnet? Yes. Many Displays only acts during the brief period after a system wake/reconnect event. For the rest of your session, other tiling or snapping tools will function normally without conflict.
5. What happens after my one year of updates ends? The final version you received during your license year continues to work perpetually. You only need to purchase again if you want feature updates or support for a future major macOS version released after your update period.