The Valve OpenVR SDK is a new development kit that has been developed by Valve specifically for creating virtual reality applications, enabling them to interact with the SteamVR hardware using the new OpenVR SDK.
The SteamVR OpenVR SDK is now available to download via github and provide support for the HTC Vive Developer Edition, as well as SteamVR controller and Lighthouse. As wells containing plenty of documentation and samples to help you get started. Valve explains :
“Along with the OpenVR SDK support has been added to support Unity via the SteamVR Unity Plugin and native SteamVR support in Unreal 4.8. Both will be available soon. This SDK release is the next step toward the first major Developer Edition shipment. If you have not yet applied to receive a Developer Edition, there is still time.”