Build small worlds.
Simulate real systems.
Simcraft is a simulation platform built on an open specification: discrete-event, system-dynamics, and agent-based models in one document format, run deterministically. Extend it with your own component libraries, take it from browser to cluster, and integrate it with the version control, data pipelines, and AI workflows you already use.
Why simulate
Every consequential decision depends on how a system will behave. A second berth at a port. A new production line. A change to the rules of a market. Testing these in reality is slow, costly, and often impossible. Simulation gives you a working model to experiment with instead: change the inputs, run the scenarios, and see how the system responds before you commit.
Beyond the spreadsheet
A spreadsheet computes one outcome from fixed assumptions. That works until the system has moving parts: things that queue, interact, and feed back over time. Systems like these rarely reduce to a formula. A simulation models how the parts behave and interact, and because it accounts for uncertainty, it gives you a range of outcomes rather than one number.
Where models live today
Most simulation models live inside the tool that made them. The model is a project file in a proprietary format. It cannot be read without a license, reviewed without a screen share, or reproduced without the same version of the same software. When the tool goes, the model goes with it, and the work that informed real decisions becomes unreadable.
Models as documents
A simulation model should be a document. Plain, portable, and readable by people and machines. A document can be diffed and reviewed like code. It can live in version control next to the decisions it informed. It can run today and again in ten years, and produce the same result to the last event. The document outlives the tool that wrote it.
An open foundation
Simcraft is built on OSDL, an open definition language for simulation models. One document format carries discrete-event, agent-based, and system-dynamics models, and runs them deterministically: same model, same inputs, same trace, every time. Engines, editors, and libraries are built around the format, not the other way around. The format is the durable asset. Everything else is replaceable.
A different way of working
Open formats change who can build. A model can be written by hand, generated by a script, or assembled in a visual editor, and each is a view of the same document. Component libraries extend the language with new building blocks. Results carry their full trace, so a claim can be inspected rather than believed. This is ordinary practice in software. Simulation is overdue for it.
Follow the work
We are building this now. The platform is young and the standard is taking shape. If open foundations for simulation matter to you, leave your email and follow along.