Show HN: Luna Display for Windows, hardware to turn the iPad into a PC display

Hi HN! I'm excited to share Luna Display for Windows, a new hardware dongle that turns the iPad into a wired or wireless display for the PC! We are long-time Mac developers who transitioned to Windows over the past 1.5 after being sherlocked by Apple (long story..)

So why hardware? There are no official APIs available on Mac or Windows for creating a virtual display. We have competitors that use low-level drivers to create a virtual display, but that is prone to subtle bugs. For example, virtual displays on Windows require reimplementing the GPU stack, which is extremely complex. We went with hardware because it's the only way to provide absolute reliability and compatibility across all PC programs. Luna Display is indistinguishable from a regular monitor to Windows.

Luna Display started as Mac/iOS apps written almost entirely in Objective-C. To go cross-platform, we selected Rust as our language of choice, and we've been incredibly happy with it. Our apps are now mostly Rust, with glue layers in C# on Windows, and Objective-C on iPadOS for the UI code.

Another interesting thing about our tech stack is that it contains a custom video compression algorithm and network protocol that we built for very low latency. The network protocol is built in Rust and sits on top of UDP and has a custom congestion control system. Our video compressor is C/C++ and a mix of assembly for max performance.

If you're interested, we'd love to have you back us on Kickstarter! I'm also happy to answer any questions about hardware, Windows, Rust, getting sherlocked, you name it. :)

PS: Luna Display also works with Mac if that's your jam!

You've probably answered this before elsewhere (so feel free to answer by adding a link), but for macOS users what's the most up-to-date comparison to Sidecar? I believe that Sidecar can't be used as the only display, whereas Luna Display can (e.g., for a headless Mac Mini, you won't be able to start Sidecar). As someone who's thought about using it for a headless Mac Mini, are there other advantages over Sidecar?

(And it would be nice to confirm that you'd recommend using Luna Display as the only display for a headless Mac Mini too.)

I previously read about what happened to you guys Re: Sidecar (my sympathies), so congrats on making this pivot to adding Windows support! This should be a huge market!

I'm curious – did you have to change the hardware dongle much, or is this mostly a software stack rewrite to support Windows?