Google has started rolling out the fourth and final edition Android O Developer Preview ahead of its official launch this summer. Compatible Pixel and Nexus smartphones, which have already enrolled in the Android beta program, will be getting an update notification for 8.0 developer preview soon.
The Android O Developer Preview 4 is a release candidate build with the latest bug fixes, which makes it up-to-date for app testing by developers. It is the final preview, of the Android O build, before the stable release later this year. The Android O Developer Preview 4 will be rolled out via OTA to all Google Pixel, Google Pixel XL, Nexus 6P, Nexus 5X, Pixel C, Nexus Player, and Android Emulator users enrolled in the Android Beta Program, as reported by NDTV.
The latest Android O Developer Preview 4 includes "near-final system images" with "latest bug fixes and optimizations, and the final APIs (API level 26)." In addition to the Developer Preview 4, the stable version of the Android 26.0.0 Support Library is also being released, as reported by The Android Soul.
Compatible device's users can register for the beta program here to receive future OTA beta versions for any OS update, and the Android O stable version when it releases later in this fall. On the other hand, the interested users can also manually flash system images as well. However, it should be noted that installing a system image on a device removes all data from the device, so the user should back up the data first.
The stable Android 8.0 O build will be released alongside the launch of the next generation of Pixel smartphone. Moreover, Google will sometime in between also show off the dessert after which Android O will be named, however, there have been some rumors floating around that it will be called as Oreo.