After number of delays from the original deadline of February 12th, OnePlus finally released Oxygen OS for its device. The company has combined features from Paranoid Android and gesture support that we saw in Cyanogen OS 11s. Based on Android 5.0.2 Lollipop, the experience looks and feels almost completely stock but as you will use it more, you will start to notice some features which are added by OnePlus for better functionality and for ease of users.
Some features according to OnePlus are:
Several original OnePlus features have been built right into OxygenOS, including screen-off gestures like double-tap to wake, music controls, and shortcuts for the camera and flashlight.
With customizable lockscreen wallpapers and the ability to switch between hardware and software navigation keys, OxygenOS allows you to make your phone distinctly yours.
With quick settings feature, tiles can be added, removed, and re-organized with the click of a button, and it blends beautifully right into the notification tray’s UI.
All being said you can download and install the ROM from the link here. The link carries the ROM with full installation instructions. But be warned it requires completely wiping the system of the device and then manually flashing it. The company did say that the automated process is under work too.
But its not necessary for you to use the OS itself, as you can continue to use Cyanogen ROMs but if you want better support from OnePlus, using this ROM wont be that a bad idea.