BadBlue is a free, small footprint web server that supports PHP, CGI and ISAPI under Windows. The newly released version supports user account management, access control to files/folders, CLF logging, IP restrictions and peer-to-peer file sharing.
Because of its small size (the core server is about 70K and the entire download is around 150K), it's a quick way to learn, develop and deploy PHP applications. BadBlue can be downloaded, installed and configured to run PHP in about a minute.
BadBlue is especially useful in mobile/wireless applications and supports out-of-the-box P2P file sharing. In addition to standard Napster/Gnutella-style sharing, BadBlue can serve up live Excel and Word data over an HTTP connection.