What is Mythoi?
Mythoi is a text-based game engine designed for interactive fiction, visual novels, MUDs (multi-user dungeons), and narrative-driven games. Leveraging Apollo (our custom language) and Morpheus (our runtime framework), it gives creators powerful tools to build immersive text-based experiences that run anywhere: from web browsers to mobile devices to standalone apps.
What kinds of games can I make with Mythoi?
Mythoi excels at text-based games: interactive fiction (like classic text adventures), visual novels, MUDs (multi-user dungeons), roguelikes, choice-driven narratives, and story-heavy RPGs. Our engine also supports rule-heavy simulations and game prototyping for tabletop RPG designers, CRPG developers, and anyone who wants to test game mechanics quickly.
Text-Based Game Engine, WTF?
Even without fancy 3D graphics, all games share fundamental requirements: object handling, concurrency, text processing, input/output, AI, pathfinding, and more. We've built a microkernel-based runtime that captures these abstract core needs across multiple game genres. You can extend the kernel with dynamic modules; examples include CCG for state-of-the-art parsing, SSH server for terminal connections, and WebSocket server for clients or dev tools. We provide full working examples for popular genres. Whether you're building a roguelike, MUD, or visual novel, Mythoi handles the heavy lifting so you can focus on creating compelling gameplay and narratives.
Isn't this overkill for text-based games?
Not really! Games, even without advanced 3D graphics, still require a great deal of plumbing. Apollo and Morpheus are built for text-based games, interactive fiction, and visual novels but also support advanced rule engineering and simulations down the line. These genres are our sandbox: a perfect starting point for crafting immersive, rule-driven experiences with MUD-inspired flair.
If I want to make a MUD, why not use existing mudlibs and drivers?
You absolutely can! Tools like FluffOS are solid, modern takes on classic MUD drivers. Interactive fiction has great options too. But here's the thing: if you want to build a roguelike with a JRPG feel, or blend MUD mechanics with visual novel storytelling, you're often starting from scratch with ncurses and C/C++, writing all the basic game systems before you ever get to the fun stuff.
Mythoi gives you a unified engine where these genres share common infrastructure. Whether you're building a MUD, roguelike, or interactive fiction, you get the same robust object handling, concurrency, AI, and networking out of the box. No wrestling with decades-old tarballs or sparse documentation; just modern tools that let you focus on your game, not the plumbing.
Is Apollo a general-purpose language?
Yes, Apollo is a general-purpose language with a prototype-based design, packed with modern features like built-in concurrency and no manual memory management. But its runtime is laser-focused on text-based games, interactive fiction, visual novels, rule-testing, and simulations.
For TTRPG, CRPG, or JRPG designers, Apollo slashes playtesting time: build immersive stories, combat systems, or NPCs in hours, not days. Tweak rules instantly with lambda constructs and see results fast.
While Apollo can handle broader use cases, our runtime is optimized for these creative goals. Curious about what's next? Join our newsletter for a peek at our roadmap!
Do I need to use Prometheus to work with Apollo?
Nope! Prometheus is our tailored IDE for crafting text-based games with stellar mapping and editing tools. Prefer the terminal? Use Alcibiades for command-line workflows and import your Codex into Prometheus anytime for mapping support.
What documentation will Apollo offer?
Expect a full EBNF/PEG grammar, detailed API docs, and comprehensive written and video tutorials. We're also including a PDF with Apollo insights to supercharge AI-assisted coding, so you can focus on creating, not decoding. We provide full examples and tutorials for multiple genres including Interactive Fiction, Multi-User Dungeons (MUDs), roguelikes, war games, and BBS doors.
What runtime environments does the Mythoi platform support?
Single-player games run on macOS, Windows, Linux, and FreeBSD with standalone apps supporting text, graphics, and audio. Deploy to the web with an Apollo Codex for instant, no-install gameplay. iOS and Android deliver seamless mobile experiences. Multiplayer games can be deployed as server/client over WebSocket or as a fully terminal-based offering with our SSH module.
Is Mythoi Z-Machine compatible?
Not anymore. Early builds supported Z-Machine output, but feedback showed fans of classic tools prefer open-source options. We're focused on propelling text-based games forward with a modern, high-performance runtime built for today's stories.
Wait, what's with the graphics mentions? I thought you were a text-based game engine?
Fair question! We should qualify this. Some MUDs use custom clients or leverage MUD protocols for out-of-band graphics support to enhance gameplay. Interactive fiction plus static images equals visual novel. It would be shortsighted to cut these use cases out of Mythoi for the sake of purity.
Our use of SSH rather than the zombified telnet protocol (which should have died with Gopher) lets us leverage separate communication channels for the same kinds of things that MUD protocols provide. These obviously require a custom client (though even some TTY terminals support things like SIXEL). For web deployments, you can create bespoke web clients that integrate graphics seamlessly. A solid example will be included in the visual novel framework.
When will Mythoi products be available?
As of February 2026, we're gearing up for a Kickstarter! Check back soon for information.
Weren't you guys just doing an interactive fiction engine before?
Yes! Life happened. Personal and professional challenges last year pushed everything back about 12 months. But we made good use of the time. We'd always planned to build a full text-based game engine, but we were starting with just the interactive fiction use case. The delay gave us the opportunity to leverage our microkernel-based approach and expand the initial scope to include MUDs, roguelikes, and more from day one. Silver lining: you get a more complete engine at launch.
Where are you located?
Our principal is in Seattle, and he'll talk your ear off at length given the slightest opportunity. He's been working on the core systems for (no joke) 30 years. He once rewrote the entire lexer/parser for Apollo in an afternoon. That's one of the benefits of prototyping Mythoi for so many years: when you know the problem space inside and out, you can move fast.
What is your future roadmap?
Check out our
Kickstarter for future plans and roadmap details!
How do I stay in the loop?
Join our newsletter to catch exclusive updates on our soft launch! Follow us on X, our forum, or Discord. For press inquiries, email pr@mythoi.io.
Cool story bro, but I hate inheritance and boomer OOP garbage from the 90s
Apollo doesn't force inheritance or hierarchies. They're there if you want them, but you can ignore all of it and use, for example, a totally flat object structure with ECS (Entity Component System) instead. Apollo's inheritance support is kind of ephemeral: it's present only as concepts. Objects cloned from archetypes aren't really objects in the C/C++ sense; they're property bags with an association to an archetype (similar to the flyweight pattern), which lends well to serialization support. None of this precludes ignoring it all and using a flatter system. Apollo's prototype-based design gives you the flexibility to structure your code however you want, whether that's classic OOP, composition-based patterns, or something entirely different.
I want to see it!
Head on over to Kickstarter, we'll have lots to see there!
Are you all mad?
as hatters.