Onshape: Full-Cloud CAD
Onshape is the first and only full-cloud 3D CAD system that lets everyone on a design team simultaneously work together using a web browser, phone or tablet.
FreeCAD is a general purpose feature-based, parametric 3D modeler for CAD, MCAD, CAx, CAE and PLM, aimed directly at mechanical engineering and product design but also fits a wider range of uses in engineering, such as architecture or other engineering specialties. It is 100% Open Source and extremely modular, allowing for very advanced extension and customization.
Creo Elements/Direct Modeling Express
Creo Elements/Direct Modeling Express is a free version of Creo Elements/Direct Modeling 19.0, the popular 3D CAD choice for leaders in product design who have short design cycles with the need to create frequent one-off designs. Its speed, flexibility and responsiveness to change also make it the ideal tool for short-series production runs.