RPI-Engine VS EmptyEpsilon

I would strongly strongly suggest investigating MUDs if that's your bag. They're non-graphical so they can be built and maintained by small numbers of people with low programming skills and they tend to be almost entirely about community experiences. I'll just leave http://www.middle-earth.us/ here because it's where I met my now SO and it's an absolutely wonderful community - but there are hundreds of them out there. They do take a serious time commitment though, since they're all about building up that interesting social world.

MUDs are a class of game that is terribly underrated. I've played on a few different one (mostly toward the RP focused end of things) but I think the whole family of games shows just how effective imagination can be when coupled solely with text descriptions.

I have extremely strong memories from Shadows of Isildur[1] and met my spouse there!

1. http://www.middle-earth.us/

A MUD I worked (uh volunteered, as a total newbie) on had a soft-reboot implementation for deploys that blew my mind when I first saw it in action. Open telnet connections were all sent keep alives before the MUD launched a new instance of itself from the executable (which may have been a different version from the currently running copy) and then killed itself. To users on the other end a message appeared saying "Relaunching the server" and was followed up shortly by "You may now resume play". Since this engine was designed to constantly fall over due to instabilities and OOMs it stored the current game state in a persistent state (originally on-disk files - most of it was migrated to MySQL) so the only things that really needed hacking were re-acquiring the right sockets and remembering which user is which.

This included, FYI, under development new game elements which were mostly written and launched using a mix of things called RPROGs, OPROGs, CPROGs and Descs (among other things) all of which were written in a custom domain language input into the MUD itself - devs like myself worked only on underlying mechanics and had no need to wander into the specifics of all those triggers.

This probably opened up a number of security holes but, given that the game only ever checked the first six characters of a password (and checked them one by one against a plaintext copy) there were lower fruit available to criticize.

If you want to check it out an older copy is available open-sourced[1] - it's a DIKU variant MUD.

1. https://github.com/webbj74/RPI-Engine

The engine is built on FOSS: https://daid.github.io/EmptyEpsilon/

Looks like they're working off a fork of a fork: https://github.com/clockwork-dog/EmptyEpsilon/commits/main/

Thorium is great; it's closer to a virtual tabletop for starship RPGs than a standalone game, built around creating interactive narratives. That sets it apart from the more straightforward game-style bridge sims, like Artemis[1] and EmptyEpsilon[2], which have scriptable scenarios with narrative elements but have more fundamentally game-focused mechanics.

All of these get used in a lot of fun ways for live events beyond their design, too. Thorium's "family tree" comes from interactive events at planetariums, and EmptyEpsilon, being open-source with an HTTP API and game-master screen for directly manipulating live game state and pretending to be ships, became a popular front-end for European LARPs.[3]

1: https://www.artemisspaceshipbridge.com/#/

2: https://daid.github.io/EmptyEpsilon/

3: https://www.odysseuslarp.com/blog/steering-the-starship-empt...

Empty Epsilon bridge simulator: https://github.com/daid/EmptyEpsilon

The game itself is fun, but the best stuff I've seen is it being reused, modified, and adapted for LARPs and crowdplay.

Out of Orbit is a great and ongoing example, a Finnish escape room-ish experience that also has a Twitch game putting stream chat in the role of the ship's AI: https://outoforbit.fi/ and https://www.twitch.tv/outoforbitgame/about

Empty Epsilon powers the game part, with integrations using its DMX interface and HTTP API to provide hardware interfaces and things like Twitch chat commands modifying the game state.

EmptyEpsilon - a free multiplayer bridge simulator. Each ship is typically crewed by 3-6 people, but you can run multiple ships in the same game or get mods that add/change roles.

"the open source": Empty Epsilon. A little more complex of a simulation than Artemis, but feels much more limited from a mission standpoint, mostly due to lack of development from that aspect. Does away with the "Star Trek" feel of Artemis for a more industrial feeling.

If you want to look at an interesting open source C++ game project that (iirc) uses SFML, you could check out Empty Epsilon.