OpenDisplay is a screen extension tool that lets you use an iPhone, iPad, or Mac as a second monitor for your primary Mac over USB or WiFi.
The tool solves the problem of needing additional display space without purchasing dedicated hardware. It works by capturing video from your primary Mac, encoding it with H.264 compression, and streaming it to a secondary device where touch input is relayed back. The approach prioritizes low latency and high-resolution support, including Retina HiDPI displays, to create a responsive multi-monitor experience.
OpenDisplay positions itself as a free, open-source alternative to commercial solutions like Sidecar and Duet Display. It suits developers and users who want extended display functionality without subscription costs or vendor lock-in. The project's support for both USB and WiFi connectivity provides flexibility for different use cases, whether you need stable wired performance or the convenience of wireless operation. The inclusion of touch input makes it practical for iPad and iPhone users who expect interactive feedback on their secondary display.
Development activity shows consistent engagement with the codebase. The project maintains an active commit history with regular updates addressing functionality and stability. Pull requests are reviewed and merged at a steady pace, indicating ongoing maintenance and feature development. Issue tracking shows responsiveness to user-reported problems and feature requests, with discussions that reflect technical depth about display streaming and input handling.
