Google has just released the first of several promised updates to the Android N developer preview. Android N Developer Preview 2 makes several major changes to the work-in-progress operating system and also includes bug fixes and tweaks to the new multi-window API.
The biggest addition is support for the Vulkan graphics API, a low-overhead counterpart to OpenGL that's analogous to DirectX 12 in Windows or Metal in iOS and OS X. It also includes support for Unicode 9.0 emoji and redesigns Google's stock emoji characters to make them "more human-looking." Unicode 9.0 is currently in draft, but it should be finalized and released this summer before Android N's final version is available. Finally, Google has added something called "launcher shortcuts," which use Intents to create shortcuts to specific in-app activities like navigating home in Google Maps or sending messages to specific people.
The Android N preview is available for the Nexus 6, 5X, 6P, and 9, the Pixel C tablet, and the General Mobile 4G; an update for the Nexus Player version of the N preview will be available soon. Those of you running Marshmallow on a supported device can update over the air by enrolling in the Android beta program, or you can flash an operating system image to your device manually. If you're already running the first developer preview, your device should receive an over-the-air update "shortly."
Google plans to release three more preview builds for Android N between now and the final release, one per month in May, June, and July. Preview 3, like this one, may make significant additions and changes to APIs. Preview 4 will see all APIs finalized and locked down and will be accompanied by a finalized SDK. Preview 5 should be a "near-final" build that's more suitable for testing by normal people, and the final build will be released sometime in Q3.