Yes, they build off other open source projects and list them in the README. I actually do run moonlight + sunshine myself, and have for more than a year. It's not too difficult to setup, depends on what you want to achieve.

I hadn't heard of wolf [0], but it checks a lot of boxes that sunshine does not. Namely, it supports multiple clients at once, multiple streams, and virtual displays out of the box (Linux + container first is almost neat). Sunshine is more for allowing your gaming desktop to be used as for game streaming. There's also a fork of sunshine, Apollo [1], that's more similar to wolf.

[0] https://github.com/games-on-whales/wolf [1] https://github.com/ClassicOldSong/Apollo

Do you also use a VPN like Tailscale for out-of-home / remote access ?