Antimony: Graph-Based CAD from Lisp Machine Philosophy

Antimony is an open-source CAD tool built on a fundamentally different philosophy than traditional drafting-derived software. Rather than mimicking physical drawing boards, it organizes design around a directed acyclic graph where nodes execute Python scripts and propagate changes automatically. The system couples this graph engine with a geometry engine using functional representations optimized for constructive solid geometry, supported by a standard library of primitive shapes and transforms.

Designs are built by connecting nodes representing shapes or operations, with changes flowing through dependencies to update assemblies automatically. The geometry engine renders functional representations as bitmaps in a 3D viewport and exports to heightmaps for 2.5D manufacturing and STL files for 3D printing, with feature detection that preserves sharp edges and corners. UI elements defined in node scripts can be dragged to feed changes back into the graph.

Active development continues at beta stability with availability for Mac and Linux. The project accepts contributions from simple Python-based custom nodes to ambitious C++ optimizations, evolving from earlier CAD work conducted at MIT’s Center for Bits and Atoms.