OnePlus has finally released their own ROM for their 2014 flagship smartphone killers after the contract termination with CyanogenMod, The new ROM, OxygenOS is based on Android 5.0.2 Lollipop with the usual goodies; Material Design, Android Runtime, improved security and etc.
The new OS is said to be “light and essential” with all customization and useful features such as; Off Screen Gestures, Quick Settings, File Manager and more.
OxygenOS is a new ROM for OnePlus One owner (using CM11S/CM12 nightlies or ColorOS) which you wouldn’t able to update it via OTA. Thus it required to download the ROM file from the official website and update it manually thru PC/Mac.
OnePlus committed with prompt updates and encourage the users to download the company’s feedback app to submit comments on the experience to build a better UI.
The installation guide and download ROM link: https://forums.oneplus.net/threads/oxygenos-is-here-installation-guide.289398/