So, to sum up:
First there was Nvidia Gamestream, which was proprietary and later deprecated by Nvidia themselves.
Then came Sunshine and Moonlight, open source server and client implementations of the protocol to allow low latency streaming for all platforms.
Along the way the Game on Whales project started, to allow multi seat streaming plus virtual displays so currently logged in user sessions aren't impacted. Basically this is a whole "host your own Stadia/Geforce Now" solution. But instead of running already setup applications as an existing user, you run these curated containers of Steam, Firefox, etc.
Then someone forked Sunshine and Moonlight into Apollo and Artemis, to make streaming from a virtual display turnkey and OOTB easy. Sadly the virtual display feature of Apollo is in practice Windows only.
And then there's this, Moonshine, in a way doing what Apollo brings to the table but for Linux servers.
Oh, and along the way someone forked Apollo into Vibepollo, an almost fully vibecoded "enhancement". Personally not touching that.
Did I miss anything?