Paizo Publishing is the company behind Pathfinder and the former publisher of Dragon and Dungeon magazines from 2002-2007. Back when Hasbro bought WotC, a whole bunch of people from the company jumped ship rather than see it get butchered from the inside. About a year after the purchase, Hasbro started slicing off or shutting down a bunch of stuff they got from buying Wizards. Paizo was started up so that the magazines wouldn't die, and took on all the magazine staff still working at Wizards.
Along with the D&D mags, Paizo also took over Star Wars Insider and Polyhedron from Wizards, and later tried starting a generalist gamer magazine Undefeated and a relaunch of Amazing Stories -- neither of which lasted more than about a year. SW Insider didn't last that long with Paizo either, moving to a different publisher due to politicking over the official Star Wars fan club.
When 4E was around the corner, Hasbro made Paizo give back the magazines, after which they were replaced with a digital app. With nothing better to do, Paizo decided they'd listen to all of us who knew that 4E would be shit, and started up Pathfinder; the rest is history.