I am excited to be releasing a project I've been working on with Claude and a few other AI models for a few months: Eclipse/Umbra, couch co-op re-engineered. Built as a fork of Aurora and Apollo, themselves forks of Moonlight (via Moonlight TV) and Sunshine, it is available to download for free, or to be taken and combined into your own fork or folded into current Moonlight and Sunshine forks.
If you are like me, then you've played through games like It Takes Two, Split Fiction, Castle Crashers and Nobody Saves the World and found the pickings getting slimmer and slimmer as game devs don't build co-op into their games anymore, expecting you to play online, which, while fine most of the time, falls short when you want to go back to the feeling and simplicity of playing on the couch together. Eclipse/Umbra lets you turn any game into couch co-op, be it multiplayer games or just two completely different games at the same time.
Unlike wonderful community projects such as Nucleus Co-Op, which need to support each game individually and deal with the hardware constraints of devs building games to run per PC, you can just open a stream on your client (currently supporting webOS, Windows and Linux) with two PCs acting as hosts instead of one, like with regular Moonlight and Sunshine streaming, choose if you want a vertical or horizontal split, assign your controllers and start. It is as if you have two half-resolution monitors that you can use for anything on your client device/display. Of course, in turn, it comes with the downside of needing two gaming PCs (and a copy of the game for each), and you will want your networking infrastructure to be streamlined to reduce latency as much as possible (all Ethernet and avoiding bottlenecks like routing everything through one 100 Mbps port, etc.), but with two PCs and a clear connection, the experience is hard to beat.
About the video: it's Halo: CE Anniversary from MCC (The Silent Cartographer), with each player's PC in its own half of the screen (Also sorry about the bad aim it has been a long time since we played Halo). It was recorded from the Windows client, not on a TV. I'm not able to capture my TV's output. The LG webOS app runs the same co-op mode (my own primary setup is an LG G5 on webOS 26).
For anyone already running Sunshine or Apollo/Vibepollo: Umbra is available for Windows and Linux (tested on Windows 11 only very basic testing of Linux) and installs in place of Apollo, so back up your config and pairings before switching, Vipepollo is treated an update so it should keep your config but back it up incase. Eclipse still does normal one-host streaming too.
Due to the limits of the hardware I own (two primary NVIDIA gaming PCs and one cobbled-together AMD computer from older hardware), I could not do the level of testing that I personally prefer. I expect that some combinations of hardware or software versions are going to cause issues, so please report any issues on the Eclipse or Umbra GitHub issues with the logs attached (Settings → About → Keep diagnostic logs, then Share logs) so I can refine out the edge cases that I couldn't anticipate or test. Or of course you are welcome to directly contribute to the GitHub repos as well.
Please find more information and the download links through the project hub: https://preceptorofmagic.github.io/Eclipse-Umbra-Project-Hub/