Windows and Quest installers use the compiled files under native/ and prepare your local disc data. Mac and Steam Deck installers build from the included source. The browser files are already compiled ...
The host registers with UU Remote as a "Windows PC", so the official clients recognize it directly. The screen is encoded to H.264 and the sound to Opus with FFmpeg, both sent over WebRTC; keyboard, ...
I thought it was a gimmick, but I was wrong.