Open Kernel Labs (OK Labs) is a privately owned company that develops microkernel-based hypervisors and operating systems for embedded systems. The company was founded in 2006 by Steve Subar and Gernot Heiser as a spinout from NICTA. It is headquartered in Chicago, while research and development was located in Sydney, Australia. The company was acquired by General Dynamics in September 2012. OKL4 is an open source system software platform for embedded systems that can be used as a hypervisor as well as a simple real-time operating system with memory protection. The OKL4 Microvisor is a variant of the L4 microkernel. The OKL4 Microvisor is a Type I hypervisor and runs on single- and multi-core platforms based on ARM, x86 and MIPS processors. OKL4 has been deployed on over 1.5 billion devices, mostly mobile phones, both as a baseband operating system and for hosting guest operating systems. Most notable and visible is the companys design win at Motorola for the Evoke QA4 messaging phone, the first phone which employs virtualization to support two concurrent operating systems (Linux and BREW) on a single processor core.