The OpenFlexure Microscope is a 3D printable microscope, including a precise mechanical stage to move the sample and focus the optics. There are many different options for the optics, ranging from a webcam lens to a 100x, oil immersion objective. The trick of making a microscope out of a webcam has been around for a little while, and produces good results. However, getting a nice mechanical stage to focus the microscope and move around on the sample is tricky. This project is a 3D printable design that enables very fine (sub-micron) mechanical positioning of the sample and the lens, with surprisingly good mechanical stability. It's discussed in various media articles and a paper in Review of Scientific Instruments (open access).