Menlo Park-based Facebook has acquired virtual reality headset developer Oculus VR, in a deal worth approximately $2 billion. Facebook said it would pay $400M in cash, plus 23.1 million shares of its stock (valued at $1.6 billion) for Oculus VR, which is based in Irvine, California. Facebook also said it will pay an additoinal $300M in earn out in cash and stock dependent on milestones from Oculus VR. Oculus VR is the maker of a popular, virtual reality headset called the Oculus Rift. Oculus VR was venture backed by Andreessen Horowitz, Formation 8, Matrix Partners, and Spark Capital.