Tinkercad is a free, web-based 3D modeling system that strives "to make 3-D design in general, and the design of physical items in particular, accessible to hundreds of millions of people." In service of that goal, Tinkercad has a very simple, intuitive, and easy to learn interface. The 3E modeling system is frequently used to teach entry-level constructive solid geometry. Objects created in Tinkercad can be exported to Minecraft and to formats used by 3D printers. In the Tinkercad Gallery linked at the top of the site, users can locate a library of objects created and shared by other users. Many of these objects are available under a Creative Commons license that allows them to be freely reused and incorporated into other projects. Tinkercad runs in any browser that supports WebGL, which includes all the major desktop browsers (Chrome, Firefox, IE/Edge, and Safari) as well as most mobile browsers.