The use of commercial gaming technology by the US military for PC-based training and mission rehearsal applications is increasing. However, deployment of this technology typically requires high-end hardware and large, lengthy software downloads; or worse, deployment via physical media and technical support. Additionally, DoD Information Assurance (IA) requirements forbid the execution of any software that has not been through an arduous certification process. Finally, the services are attempting to standardize computer and networking resources to specifications geared towards typical office applications (e.g., document editing, email, web browsing, etc.). These platforms typically have a multiyear refresh cycle so that any particular computing station could be up to 3 years old. Networking performance is "sized" for office expectations and not interactive content delivery. The push to adopt gaming and simulation platforms for interactive training is running counter to the push to standardize computing and networking platforms across the DoD. Services often cannot afford the costs of deploying additional equipment and resources for gaming and simulation-based training. Web client solutions, interactive applications that work primarily within a web browser environment, run on existing DoD computing and networking assets. The US Air Force and Navy have teamed to achieve a highly interactive web-based mission rehearsal trainer capable of being delivered through the browser on a typical enterprise desktop computer. This paper discusses the requirements, trade-offs and technology researched this year to meet this need.