Xbox One S Wireless Controller (Bluetooth and Steamlink) (PC Gaming) - YouTube
How to Set up a Steam Link Device in 6 Simple Steps
Best Steam Link Controllers and Couch Gaming Lapboards | RealGear
How to Remap Xbox, PlayStation, and Other Controller Buttons in Steam
In addition to Xbox 360 and Xbox One controllers, it was discovered that Steam Link also supports PS3 and PS4 controllers. I decided to give my Wii U Pro controller a shot. :
Steam Link Launches on macOS, Enabling Game Streaming to Mac - MacRumors