>>403Games and apps must be created with a compatible SDK of the HMD you intend to use (for example Oculus Rift -> OculusSDK/SteamVR, HTC Vive-> SteamVR).
OSVR is an open source SDK so every hardware manufacturer can use it to create their HMD software, but I gotta say that Valve intends too to let other manufacturers create SteamVR compatible HMD, and Oculus too but It isn't as clear than Valve.
Recently OSVR support was added to Unreal Engine and Unity so there will probably be more OSVR games in the future but right now there is only a few or none, it's more a dev kit than a consumer product.
Talking about product, the OSVR dev kit is vastly inferior than the Oculus Rift or the HTC Vive.