Dragonstar is a science fantasy setting using d20 material. The Dragon Empire rules a galactic empire with ten dragon houses corresponding to the five chromatic and five metallic dragon colors. The various d20 races, including humans, halflings, elves, dwarves, half-orcs, et cetera, can be found across the varied worlds of the empire. Science fiction technology is merged with magic, so you have machine guns mixing happily with wands and so forth.
The product website is still up, though they've stopped supporting it:
https://www.fantasyflightgames...products/dragonstar/