OxygenOS (Chinese: 氧OS; pinyin: yǎng OS) is an Android-based operating system (OS) developed by Chinese smartphone manufacturer OnePlus exclusively for their smartphones. OxygenOS was developed for their overseas market.[1] There used to also be another version of the OS designed specifically for the Chinese market called HydrogenOS (Chinese: 氢OS; pinyin: qīng OS).[2]
In an interview published on 3 September 2016, XDA Developers revealed OnePlus was "actively merging both platforms (OxygenOS and HydrogenOS) into a single cohesive operating system based on Android".[3]