In September 2005 the United States Army's Tank-Automotive Research, Development, and Engineering Center (TARDEC) instituted a ground mobility, robotics systems integration and evaluation laboratory: the TARDEC Robotics Skunk Works. The goal of this laboratory is to integrate and assess new and developing unmanned systems technologies to support efficient transitioning of the technologies to ATO and PM/PEO programs. The first unmanned system to enter the TARDEC Robotics Skunk Works will be the Tactical Amphibious Ground Support System - Common eXperimental (TAGS-CX). Key development design requirements for this modified COTS platform, which weighs less than 2 tons, include modularity and interoperability of ground robot systems and mission payloads. The overall TAGS-CX concept is to have one general purpose, high-mobility platform that provides a standardized mechanical, electrical, and messaging interface to allow numerous heterogeneous “plug-and-play” payloads to be installed, possibly simultaneously. By standardizing at each of these levels, the TAGS-CX platform can easily be configured for a number of different missions, a capability not provided by any presently available unmanned ground system. Possible payloads may include lethal and less-lethal weapons modules, a manual drive-by-wire module, combat casualty care modules, storage modules, fuel modules, and serial manipulator modules. The Joint Architecture for Unmanned Systems (JAUS) will enable this “plug-and-play” capability by providing a standardized C2 interface for the OCU, TAGS-CX platform, and the payloads. We will present the overall design and concept of operations of the TAG-CX platform and discuss some of the payloads that are being developed.