After two developer previews, Android 8.1 Oreo is ready for the masses. Google announced that the new OS is rolling out now and is posting system images for the Pixel 2 and 2 XL, the Pixel 1 and 1 XL, the Pixel C tablet, and the Nexus 6P and 5X. The Android Open Source Project (AOSP) code drop should be happening now, too. Android 8.1 Oreo is a minor maintenance release after the major update of Android 8.0. The biggest feature in 8.1 is a new "Neural Networks API" (NNAPI), which is designed for running machine-learning operations on mobile devices. Phones with specialized machine-learning hardware can hardware accelerate this API, while older devices can use a CPU fallback mode. The API provides a base layer, higher-level, machine-learning framework to plug into, like Google's TensorFlow Lite.