The U.S. Army has realized the need to change its procurement strategy to demand shorter equipment fielding times, delivering capabilities with clear military value that can be improved in low risk increments. This paper addresses the need for a C4ISR infrastructure based on open standards that can be sourced from multiple vendors and host the full spectrum of applications. The Distributed Computing Environment (DCE) -- is a computing and network infrastructure scalable from handheld and dismounted form factors through redundant, distributed clusters supporting multiple secure enclaves, and qualified for the most stringent of ground combat environments. The DCE captures the benefits of commercial-off-the-shelf (COTS) capitalization surrounding the x86 architecture, and implements open standards including OpenVPX, POSIX, Gigabit Ethernet, the Object Management Group Data Distribution Service, and the Service Availability Forum. Packaged COTS subsystems implement the hardware as rugged chassis comprised of industry standard backplanes with fully integrated computing and I/O modules. The result is rapid availability for high technology readiness level equipment that delivers field-proven technology that will last the lifetime of a combat vehicle, and has a clear technology upgrade path when required.