OnePlus announced the name of the custom custom ROM that the company is preparing for the international version of the One: OxygenOS. The Chinese version of the smartphone will receive a specially customized version of the ROM called HydrogenOS (H2 OS).
http://www.notebookcheck.net/OnePlus-announces-OxygenOS-the-company-s-own-custom-Android-ROM.135487.0.html