ddcutil vs Lunar

ddcutil is a free Linux program for controlling monitor settings such as brightness, color levels and input source. It communicates with monitors through DDC/CI over I²C and supports monitors implementing MCCS over USB. Commands can find monitors, show capabilities, read or change VCP feature values, and save or restore color-related settings. The companion ddcui provides a Qt graphical interface with Summary, Capabilities and Features views, with the last allowing changes to modifiable values. For profile workflows, dumpvcp saves current settings to a file and loadvcp restores them. Developers can use the C API through libddcutil.so to read and write VCP values and handle profile-related features. The program is released under GNU GPL version 2. Setup requires the Linux kernel i2c-dev module, and non-root users need permissions to run it. It does not support laptop displays, which use a special API rather than I²C, and generally will not run in virtual machines because virtual video drivers do not implement I²C. For MCCS-over-USB table features, support is limited; the capabilities command synthesizes a response.

Lunar is a macOS app for controlling monitors, including external monitor brightness, volume and input. On compatible monitors it uses DDC to send brightness and input commands directly. Manual Mode provides hotkeys for external-monitor adjustments, while Sync Mode copies the MacBook’s adaptive brightness changes to external displays. Sensor Mode adjusts brightness and contrast using an external ambient light sensor; Location Mode responds to the sun’s position. Clock Mode schedules changes by time or by sunrise, noon or sunset. Pro features include XDR Brightness, sub-zero dimming, Auto BlackOut, BlackOut and FaceLight. Lunar also works with macOS Shortcuts and includes a command-line interface for monitor automation. It supports macOS 11 and later and runs natively on Apple Silicon and Intel. When DDC is unavailable, Gamma can dim a display but cannot change its volume or input. The free version permits 100 Manual Mode adjustments and 100 Shortcuts action calls per day. Lunar Pro costs $23.00 USD as a lifetime license.