Precision 3D for the things you build.
Serpentine3D is a free modelling and drafting tool with the exactness of Rhino — true curves, real dimensions, and drawing sheets a workshop can build from. Made by one person who needs it, not a software company.
Curves that measure true
Surfaces here are real mathematics, not triangles — the same NURBS geometry Rhino uses. A 300 mm radius is a 300 mm radius at any zoom, on any drawing. It opens and saves Rhino .3dm files (curves exact, layers preserved), and exports STEP, DXF, glTF and USD for the rest of your pipeline.
From model to drawing sheet
Paper-space sheets from A4 to A0 with live detail views at real scales — 1:25, 1:50 — plus hidden-line technical views, dimensions, leaders, hatching, scale bars, title blocks and revision tables. Print straight to PDF and hand it to the workshop.
Your Rhino muscle memory works
A command line that speaks Rhino — move, loft, fillet, offset — with the same aliases, object snaps and a gumball for direct manipulation. If your hands know Rhino, they already know this. If they don't, there's a menu for everything.
Model with an AI that can see the screen
Serpentine speaks MCP, so an assistant like Claude can look at your viewport and run any tool you can — draw a curve, run a boolean, export a STEP. Describe the change and watch it happen, or hand off the repetitive parts and keep designing. The same engine runs with no window at all — a script, a batch of a hundred variants, a CI job on a server with no display. No other CAD tool is built to be operated this way.
Get it on your machine
Serpentine3D runs on Linux, Windows and macOS — every build free, no account, no subscription. Pick your platform below.
| REV | PLATFORM | STATUS | NOTES | |
|---|---|---|---|---|
| A | Linux | ISSUED | One-file AppImage. Download, make it executable, double-click. No admin rights needed. | DOWNLOAD ↓ |
| B | Windows | ISSUED | One-click installer, 100 MB. Windows may flag it once — choose More info → Run anyway. | DOWNLOAD ↓ |
| C | macOS | ISSUED | Drag-to-Applications disk image, Apple Silicon. Unsigned for now — right-click → Open the first time. | DOWNLOAD ↓ |
Every platform, shipped
Linux, Windows and macOS builds are all live — same modeller, same files, version 0.8.3. Free, open source, no account, no subscription.
Start with a scene, not a blank viewport
New here? Download a sample, then File ▸ Open it —
real geometry to explore and learn from, instead of floundering with
primitive shapes.
Keep the lights on
Serpentine3D is free and always will be. No subscription, no licence server, no “upgrade to Pro.” One person builds and maintains this in the hours between other work.
If it’s useful to you, a small contribution helps keep development moving: bug fixes shipped, features added, servers paid for. Not required. Never expected. But genuinely appreciated.
Technically inclined? The source code and issue tracker live on GitHub — contributions welcome.