VPN-Cube is a management tool for controlling topology, addressing and security on a cloud platform. It builds on top of an open source virtual private network application, OpenVPN, to create an encrypted LAN inside a single cloud or an encrypted WAN across multiple clouds. This allows the cloud based clusters or the hybrid cloud-enterprise datacenter ecosystem to appear as a single physical network. Versions have been adopted for quick deployment on Amazon EC2 but other platforms are supported.