Open Source

We build in the open. Rational Boxes develops and sponsors open-source platforms for document-heavy and design-heavy practices: the kind of infrastructure our clients would otherwise rent from a vendor who owns their data.

You can read the code, run it on your own servers, and keep using it whether or not you work with us.

FileEngine and Proxima File Vault

The document platform you actually own

FileEngine is an open-source platform that stores, serves, edits and reasons over documents and models. Proxima File Vault is our hosted service for it.

  • Versioning. Every change is a new immutable version, and the filesystem can be restored to any earlier state.
  • In-browser editing. ONLYOFFICE for Office files, PDF.js for PDF annotation, and Xeokit for 3D, BIM and CAD models.
  • AI over your own documents. Retrieval-augmented chat and semantic search, scoped per user so an answer never leaks a file that user cannot open.
  • Folder automation and review. Folder actions can auto-sort files with a classifier, raise reviews and call webhooks.
  • Open interfaces. A C++17 core reachable over gRPC, REST, WebDAV and MCP, with content in any S3-compatible store, encrypted and compressed at rest.

It is built for design and construction teams, sustainability and compliance specialists, manufacturers, engineering teams, and software teams that need to embed a file store.

Dashboard with reviews and recent document activity Comparing two versions of a BIM model, with review comments

License: AGPL v3 for the core, LGPL v3 for the client libraries, and MIT for the integration kit.

Visit Proxima File Vault

BIM Riviera

Open-source BIM on native IFC

BIM Riviera is parametric BIM for architecture, structure, MEP and sustainability. Your model is an ordinary IFC file (IFC2X3, IFC4 or IFC4X3), not a proprietary container.

  • Structural framing and analysis. Steel and timber sections, a linear static solver, and a Results Explorer.
  • Scripting and AI. Every operation is a command with a published schema, runnable from the ribbon, from Lua scripts, or through a built-in MCP server.
  • Specialist design modules. Greenhouses, accessible bathrooms and spas, and sustainability studies covering energy, daylight and embodied carbon, with gbXML and HBJSON export.
  • Coordination. Clash detection, BCF 2.1 and 3.0 issue tracking, and team sharing through BIMserver and FileEngine.

Riviera is at a very early stage. Pre-release packages are available for Linux, Windows and macOS (Apple silicon).

The Manor sample drawn see-through in 3D, its roof selected A two-story steel frame with bending moment diagrams and the Results Explorer

License: GNU GPL v3.0 or later. Its open data formats and protocols are MIT-licensed.

Visit BIM Riviera · Source on GitHub