The greatest challenge for open source is to extend the open source and open standards at the heart of the Internet. Projects such as Bind, Apache, and Sendmail and the BSD TCP/IP stack have been at the heart of the current generation of Internet applications. We are now faced with a unique opportunity to define the architecture of a next-generation network operating system that includes xml-based web services, decentralized systems for file sharing, collaboration and identity, and support for an ever-growing range of connected devices. Microsoft's .Net and Sun's SunONE are two visions for this operating system; will the many next-generation open source projects crystallize into a legitimate alternative?