After studying the history of legibility/readability experiments, both those done by scientists and those done by type designers, I designed two typefaces, Matthew Legible and Matthew Readable. Matthew Legible's open, simple forms are meant to increase legibility for general use (not for a specific purpose, such as screen-based legibility). Matthew Readable is designed to be read quickly and easily by experienced readers with good vision (readability for children just learning to read or for people with low-vision would require a different design).
You can download these fonts here, and use them however you wish. Note that Matthew Readable is an incomplete font, with only the lowercase set fully finished.