Free CAD and mesh tools cannot match Rhino's trimmed NURBS surfacing and its Grasshopper-driven parametric modeling.
About this gap
Rhino, Rhino 8 commercial license, one user
$995 USDone-time
≈$1,418.57 CAD one-time (converted from USD)
Build effort
Years, or a funded team
An editor’s estimate for a free tool that ranks Strong.
Demand
Nobody has asked for one yet.
What a free alternative needs
The capabilities that keep people paying for Rhino.
1
Reliable NURBS surface modeling and trimming
Free-form surfaces that stay watertight through trims, fillets and blends.
2
Booleans and solids on trimmed surfaces
3
Visual parametric scripting
A node-based environment such as Grasshopper that drives geometry from parameters and data.
4
Plug-in ecosystem for fabrication and analysis
5
Clean 3DM, STEP and IGES exchange
Why it is hard
Trimmed-surface intersection kernels are hard to get right. McNeel publishes the openNURBS toolkit for 3DM files, but the Grasshopper plug-in ecosystem has no free equal.
Closest free options
Each covers part of the job. None replaces Rhino yet.
Partial: Parametric NURBS solid modeler with a small tool set and no free-form surfacing.
License: Open source
Windows
macOS
Linux
Status: Unknown
STEPSTEP: saves only, partial fidelity. STEP export is listed on the project site; STEP import is not
STLSTL: saves only, partial fidelity. Exports triangle meshes for 3D printing
DXFDXF: opens and saves, partial fidelity. 2D geometry only
Building one?
List your tool on Gratistack when it works. Once an editor maps it to Rhino, it shows on this page and in search, and the people waiting here can hear about it.
Listing is free. An editor reviews the free queue every week.
Want a decision sooner? The optional $49 fast-track gets one within 48 hours. It buys speed, not approval, and a rejection is refunded.
Once it is listed as an alternative, you can sponsor the alternatives page for $149 per 30 days. Sponsors are labeled and never change the ranking.