Obviously slide film produces positive transparencies; has anything produced positives directly onto some sort of photographic paper or reflective material when developed (other than Polaroid and other instant film types)?
The Daguerreotype was the first practical photographic method (1835) yielded a positive image on a silver plated copper plate. The image is actually a negative however it appears positive because of the highly polished reflective surface behind it. Actually it was Sir John Herschel in 1839 that realized that any weak negative viewed against a highly polished reflective background appears positive. The outcome was collodion positives called ambrotypes. Next metal plates were painted gloss black and then coated with light sensitive goodies, these were the tintypes. After that, many reversal processes appeared; mainly they found use in photo-booths in the 1940s. Color direct positive prints on paper came next.
All photo papers, which are (or were) produced to make prints from positive film, can also be exposed directly in a camera and developed directly into a paper positive.
The last available colour positive paper was the Ilfochrome product series from Ilford. Production was discontinued in 2011.
There is still quite a few manufacturers of B&W papers (search for 'direct positive paper') for this purpose, some of which have emerged over the last few years during the retro analog wave. In theory, you could even process any regular 'negative' photo paper in a reversal process and obtain a direct positive print of some sorts, just by modifying the development process.
This is usually done in large format cameras, since 135 and even medium format cameras would produce rather small prints.