Fork reality. Explore what happens next.
One engine. Any world.
Enreef turns places and ideas into living worlds. Change housing, transit, businesses, resources, rules, or entire systems — then run time forward and watch the world respond.
See how it works ↓Fork reality
Change one thing. Watch everything respond.
Fork San Francisco. Convert downtown office space into housing, increase transit service, run both branches forward, and compare where they diverge.
A living system
A city isn't a map. It's millions of decisions.
Housing changes commutes. Jobs change travel. Infrastructure changes opportunity. Businesses respond to demand. Institutions change the rules.
Enreef runs those systems together. Change one layer and the rest of the world can respond — from individual households to citywide patterns.
- L10People
- L09Households
- L08Relationships
- L07Housing
- L06Jobs
- L05Businesses
- L04Mobility
- L03Institutions
- L02Infrastructure
- L01Geography
Enreef Worlds
Create a world. Let it keep living.
Define a place, population, economy, institutions, history, and rules. Enreef turns them into explicit world state, fills the world with people and organizations, and runs it forward through time.
"Create an isolated Pacific island in 2035 with 10,000 residents, expensive housing, a tourism economy, limited energy, and two political movements competing over development."
Kepler Island · 2035
World ready- Geography
- Population
- Households
- Housing
- Businesses
- Institutions
- Economy
- Relationships
- World rules
- History
Descriptions become structured state and rules you can inspect, edit, run, and fork. Explore Enreef Worlds →
Persistent worlds
They don't wait for you.
People go to work. Businesses open and fail. Families move. Relationships change. Neighborhoods grow. Institutions react. History accumulates. Leave the world. Come back later. It moved on without you.
Kepler Island · 2035
A new harbor town
Mina takes a job near the waterfront as the first businesses open.
Kepler Island · 2041
The town connects
Transit arrives. New jobs pull households toward the growing center.
Kepler Island · 2052
Pressure changes the city
Housing tightens. Families move inland while new firms fill the waterfront.
Kepler Island · 2070
History has accumulated
A generation of decisions has reshaped the economy, neighborhoods, and skyline.
Leave for a week. The world keeps living.
The platform
Compile reality. Or create it.
Earth and Worlds look different on the surface. Underneath, they run on the same Enreef Engine.
Enreef Earth · Real places
Run the real world forward.
Start from real geography, population, housing, businesses, transit, infrastructure, and institutions. Fork a place and explore how change moves through it.
Explore Earth →
Enreef Worlds · Created places
Create a world. Let it live.
Define a world from a description, rules, data, or an existing branch. Its people, businesses, relationships, institutions, and history keep moving forward.
Explore Worlds →
Enreef Engine
One engine. Any world.
World state, time, people, organizations, rules, history, branches, and inspection live in one shared system. See the technology →
One engine
Build. Run. Fork. Inspect.
Real places and created worlds use the same primitives: state, time, people, organizations, rules, history, and branches.
1.Build
Start from real data or define a new world from geography, population, history, resources, and rules.
2.Run
Advance time as people, businesses, institutions, infrastructure, and world rules act on one another.
3.Fork
Branch from any checkpoint, change the world, and let alternate histories unfold independently.
4.Inspect
Compare branches and trace what changed, where it changed, and the decisions and events behind it.
Enreef Earth
Every real-world future earns its credibility.
A convincing outcome is not evidence. Enreef keeps the sources, assumptions, versions, branches, and history behind every Earth run inspectable — and uses historical replay to measure where a model holds up and where it does not.
- Sources
- Every Earth world records the data, licenses, snapshot dates, and build inputs behind it.
- Historical replay
- Run known past conditions and compare the resulting world with what actually happened.
- Calibration
- Models are measured against observed data, holdouts, and simpler baselines instead of trusted by appearance.
- Uncertainty
- A branch is not presented as the one inevitable future. Assumptions and uncertainty stay visible.
Enreef Worlds
Created worlds answer to a different standard: their authored rules, continuity, relationships, resources, and history must remain coherent over time.
Go deeper in Researchand Technology.
Come build living worlds.
Enreef makes worlds runnable. The hard part is making them fast, persistent, coherent, inspectable, and alive across years of accumulated history.
- Rust world-engine engineering
- Geospatial systems
- Behavioral modeling
- Agent systems
- Visualization
- Distributed systems
- Product design