Abstract : Welcome to the Fiscal Year 2009 edition of the Army Research Laboratory (ARL) Annual Review. This publication is our opportunity to provide the reader a brief look at who we are and highlight some of the significant achievements of the past year. We are a diverse organization with a wide variety of research and analysis expertise and capabilities that touch on virtually every area of scientific endeavor. What you will see here will therefore be only a representative sample of the on-going efforts of the ARL. ARL s research continuum stretches from early, long-term, basic research to evolving new technologies to support current operations. We organize our research and analysis programs within nine Technology Focus Areas: Extramural Basic Research, Networks, Human Dimension, Lethality, Protection, Mobility, Power and Energy, Sensors, and Survivability/Lethality Analysis. Throughout this review there are several references to on-going and new initiatives to ensure ARL stays on the forefront of technological change and has the capability and agility to adjust and adapt to new ideas and breakthroughs on a real-time basis. These initiatives range from outreach and collaborations, to improvements to our facilities and equipment and high-risk/high-payoff seed projects in emerging, exploratory and expanding fields. Regardless of the initiative, the concept is the same to keep ARL a vibrant, world-class research facility that can attract and retain outstanding scientific and engineering professionals. This is a never-ending pursuit that has no finish line, and no end to challenges, but as you will see in these pages, it is one we are winning. This review begins with an introduction that includes our organization, personnel, infrastructure initiatives, awards and other recognition earned by ARL and its personnel, and support to current operations. The remainder of the publication is structured around the nine TFAs identified above.