OnShape
Unlike file-based CAD, which relies on fragile file references and slow check-in/check-out procedures, Onshape uses the full power of cloud architecture to transcend these limitations. Cloud-native CAD provides a centralized repository of design data, eliminating the problems of lost data and the need for users to manage their own files. Onshape is accessible on any web browser, allowing users to access, manage and share their design data securely from anywhere in the world on any web-connected device.
Thingiverse
Thingiverse is a website dedicated to the sharing of user-created digital design files. Providing primarily free, open-source hardware designs licensed under the GNU General Public License or Creative Commons licenses, the site allows contributors to select a user license type for the designs that they share.
OpenSCAD is a software for creating solid 3D CAD objects. It is free software and available for Linux/UNIX, MS Windows and MacOS.
OpenJSCAD.org is a more up-to-date OpenJsCAD frontend where you can edit .jscad files either locally or online via JS editor (built-in). A few functions are available to make the transition from OpenSCAD to OpenJSCAD easier (OpenSCAD.
MakerSCAD is a web-based parametric 3D design software with a block-based programming language to create objects for 3D printing, animations, games and websites.
ImplicitCAD is a project dedicated to using the power of math and computer science to get stupid design problems out of the way of the 3D printing revolution.
OpenJSCAD.org is a more up-to-date OpenJsCAD frontend where you can edit .jscad files either locally or online via JS editor (built-in). A few functions are available to make the transition from OpenSCAD to OpenJSCAD easier (OpenSCAD.
MakerSCAD is a web-based parametric 3D design software with a block-based programming language to create objects for 3D printing, animations, games and websites.