MICROSOFT INTERNET SECURITIES AND ACCELARATOR SERVER
Microsoft Internet Security and Acceleration Server (ISA Server) is described by Microsoft as an "integrated edge security gateway". Originating as Microsoft Proxy Server, ISA is a Firewalling & Security product based on Microsoft Windows primarily designed to securely publish webservers and other server systems, provide Stateful, Application- Layer Firewalling, serve as a VPN endpoint, and provide Internet Access for client systems in a Business Networking environment.
ISA 2000 and 2004 have as well been incorporated in the Premium Edition of Microsoft Small Business Server, as well as being sold as Appliance devices by a number of Third Party vendors.