FreeCAD is a full featured open source parametric modelling CAD, and the only open alternative for professional CAD (at least for professionals that look for a similar feature set than in privative software).
FreeCAD can be extended in many ways thanks to the concept of workbenches, but the most common ones are Part design (parametric modelling) and Assembly 3 or 4 (for mechanical integration of parts).
Requirement notes
Multiplatform: ✅
Free / Open source: ✅
Active project: ✅
FreeCAD is a healthy project with mayor releases approximately each year.
One of the main FreeCAD contributors (RealThunder) has its own fork known as FreeCAD Realthunder, in which he experiments with some features than may later release on the official branch. Some people considers this some kind of unofficial unstable FreeCAD branch.
Low entry barrier: 🔴
FreeCAD UI and UX is infamously hard for beginners. Because using non-common abstractions and non-common own terminology.
FreeCAD usage (even basic) can result in very obtuse errors, that are useless for people not already familiar with the app.
To be proficient in FreeCAD it is also required to know the quirks of OpenCASCADE, and the topology mapping behavior/limitations of the app.
Non-linear: ✅
Part design workbench provide non-destructive parametric modelling.
Fast prototyping: 🔴
FreeCAD combination on unintuitive UI and strict parametric modelling would make it a slow tool for prototyping.
Collaboration: ⚠️
Standard FreeCAD savefiles are binary.
Realthunder FreeCAD fork provides an option to save the projects as a collection of XML files. (see example).
Assembly: ✅
Assembly 3 workbench (also authored by Realthunder, but available in the standard FreeCAD) is a very powerful assembly solution, and the most common workflow for assembly within FreeCAD.
Intro
FreeCAD is a full featured open source parametric modelling CAD, and the only open alternative for professional CAD (at least for professionals that look for a similar feature set than in privative software).
FreeCAD can be extended in many ways thanks to the concept of workbenches, but the most common ones are
Part design(parametric modelling) andAssembly 3 or 4(for mechanical integration of parts).Requirement notes
Part designworkbench provide non-destructive parametric modelling.Assembly 3workbench (also authored by Realthunder, but available in the standard FreeCAD) is a very powerful assembly solution, and the most common workflow for assembly within FreeCAD.