Johannes Hevelius is a XVII century astronomer, who authored, among other things, the celestial atlas Firmamentum Sobiescianum sive Uranographia. If you are interested in astronomy, there is a good chance that you have seen at least one of the Uranographia‘s artistic depictions of the constellations – as an illustration in a book or somewhere else.
Mark Crossley has created a new “sky culture” for Stellarium that displays these engravings as constellation art. It is still a work in progress: not all constellations are there (and some will never be, as Hevelius published before the current 88 constellations were officially established) and the quality of the images varies. Some of the images are high-quality scans by the Space Telescope Science Institute (HubbleSOURCE: Constellation Mythological Forms), others are scans from elsewhere with lower resolution.
Unfortunately, according to the HubbleSOURCE site, these images can only be used “in planetarium shows, exhibits, videos, and other non-commercial applications.”, so the sky culture can’t be licensed under a free license and distributed together with Stellarium’s main distribution. (But this also means that the people who not-very-ethically sell Stellarium on eBay won’t be able to sell it too.)
An 8 MiB archive containing the current version of the sky culture can be found on Mark Crossley’s website:
Wilmslow Astro » My Software & Stuff
(Scroll down to “Stellarium Hevelius Constellation Art”.)