OxygenOS
In 2014, OnePlus promised the experience is "close to pure Android, without bloation and with great customization capabilities." Soon they held a contest "Name the firmware" in search of a name. On 30 January 2015, OnePlus officially announced the names OxygenOS and HydrogenOS. The winner of this @Midifire from Belgium was taken to the headquarters in Shenzhen, where he met with the team with their general manager Pete Lau.