In wired Ethernet networks (IEEE 802.3), a physical network interface can be connected to different network segments or shared among multiple virtual machines. In wireless LAN (IEEE 802.11) sharing a wireless network interface is recognized to be a difficult task. However, virtualization can solve this problem. In this paper, the authors will introduce a software platform for hosting multiple virtual wireless networks over a shared physical infrastructure by means of open source virtualization techniques. They present the design, implementation, and performance testing of this platform.