__exclusive__ - Moi 3d V5 Free

A fully open-source parametric modeler. It has a steeper learning curve but offers professional-grade NURBS tools for $0.

There are in the trial – it's the full software, time-limited. moi 3d v5 free

Often called the "MoI for the modern era," it has a similar artist-friendly workflow and a very generous trial. A fully open-source parametric modeler