EVE Online's Carbon Engine Goes Open Source Under MIT License

Carbon Engine Goes Open Source: EVE Online's Tech Now Available on GitHub

Fenris Creations has released the Carbon game engine—the tech powering EVE Online for over two decades—as open source on GitHub. The engine is available under a permissive MIT License for most modules, with spatial audio clustering under Apache License 2.0 and the IO module under the Python Software Foundation License. No commercial restrictions apply: anyone can use Carbon for free, build their own MMO, or fork the engine.

Ben Hunter, senior development director for core technology at Fenris Creations, explained the rationale: "We wanted to get the code out there for inspectability and building trust with the community." The decision came after realizing that "there's nothing really special about our sauce in terms of the actual code." The open-sourcing follows a two-year preparation period, with the bulk of the work completed in the last 12 weeks.

Security: A Double-Edged Sword

Open sourcing a 23-year-old engine raises obvious security concerns. Hunter acknowledged that bad actors will probe for exploits, but argues that "the holes that were there would have been there anyway." He noted that the community has already submitted pull requests for security fixes, and the number of security-related PRs has been minimal, reflecting "battle-hardening" from years of large-scale fleet fights and attempted disruptions.

Governance and LLM Disclosure

Fenris consulted the Godot engine team for guidance on governance models. The key insight: make good architectural choices, specifically a plugin architecture, to define contribution surfaces. Fenris is implementing a plugin system for Carbon and will open-source the tooling in the coming months.

Contribution guidelines require disclosing if an LLM was used to generate code. Hunter explained: "We don't mind you using an LLM, but you have to disclose it because we may subject it to different scrutiny." This pragmatic approach acknowledges the reality of AI-assisted development while maintaining code quality.

What's Open and What's Not

A significant challenge was separating the engine from two decades of accumulated game-specific code and middleware with incompatible licenses. The in-game economy—estimated to handle over $50 million in trading volume annually—remains closed source. "We had to make very careful considerations for what we carved out," Hunter said.

Future Plans: Test Project and Plugin Architecture

Fenris plans to develop Carbon in the open, which will increase scrutiny on architectural changes. The team needs to create a test project—an example game—to simplify testing without jumping into EVE Online or EVE Frontier (the crypto-integrated survival game). This test project will become the team's primary test space.

Industry Context

Hunter sees the engine landscape shifting: "Developers that were traditionally going to Unity or Unreal starting to shift gears towards Godot." He pointed to Epic's recent Unreal Engine 6 announcements and the integration of AI. Carbon's large-scale persistence model, which has been battle-tested in EVE Online, is now being emulated by other engines.

Fenris also built an internal tools gateway for LLM interfaces, which will be open-sourced after hardening. This aligns with the industry trend of integrating LLMs into development workflows.

How to Get Started

Carbon is available on GitHub. Clone the repository, review the contribution guidelines, and check the license specifics for each module. To build, you'll need the appropriate build tools; the repository includes a README with setup instructions. For those interested in the plugin architecture, keep an eye on the upcoming open-source tooling release.

The Bigger Picture

Hunter hopes to see a large, EVE-centric community building "their own augmented versions of the game experience." He draws a parallel to the API release years ago, which spawned third-party apps for skill management and ship fitting. With the full engine, the potential is much greater. As he put it: "Rising tides lift all ships. If we improve the code and we can all benefit from it, it's good for everyone."