Render Legion’s development of Corona Render for Cinema 4D has been pretty steady. Along the way they have posted a few previews for new features, showing off developmental milestones. Recently, a new post shows how you can set up and HDRI sky in Corona C4D.
Corona was developed to be a high performance unbiased photorealistic renderer, initially for 3ds Max. other hosts are currently under development including Maya and Cinema 4D. Interestingly, the Corona project started as a student driven endeavour, from Ondrej Karlík at Czech Technical University in Prague.
The tutorial demonstrates how you can set up and HDRI sky as lighting and background, or as background only using Corona for Cinema 4D.
Note that this is a preview. While the C4D plugin is under development, there may be changes to the interface or functionality in the final release, but it all looks really promising so far!