What you can build today
Open BIM software, built your way.
Build web-native BIM apps without vendor lock-in.
Stream massive BIM models and collaborate in real time.
Read, edit and create BIM data with Fragments, the web-native open BIM format.
Integrate with your stack (IFC, databases, cloud, GIS).
Control your data and monetization on your terms.
Why it's different
Why open-source BIM is different.
Open by default (MIT license)Use it, modify it, ship products.
Performance by designBinary, lightweight, deduplicated data flows.
Future-proof & interoperableWorks alongside IFC and modern web stacks.
Community momentumTalent you can hire, knowledge you can reuse.
Commercial freedomYou own your IP, pricing and roadmap.
The open-core model
Open foundation. Platform on top.
FormatFragmentsA performance-focused, open foundation for streaming and querying.
LibrariesThat Open EngineAn open-source viewer and tools to build web-native AECO apps.
PlatformThat Open PlatformWhere it all comes together: ready-to-use apps, AI agents and your own apps, running on your projects.Explore the platform → When to use what
Pick your path.
Building and hosting your own product, with a dev team?
Use Fragments + That Open Engine. If you want strategic and technical guidance while you build, join That Open Accelerator.
Want to use it, not host it?
That Open Platform is the way. And if you need a specific app, we build it for you through the Custom Apps Program.