The purpose of this book is to define barriers and challenges to a rapid expansion of cellulosic-ethanol production and determine ways to speed solutions through concerted application of modern biology tools as part of a joint research agenda. Although the focus was ethanol, the science applies to additional fuels that include biodiesel and other bioproducts or coproducts having critical roles in any deployment scheme. The core barrier is cellulosic-biomass recalcitrance to processing to ethanol. Biomass is composed of nature's most ready energy source, sugars, but they are locked in a complex polymer composite exquisitely created to resist biological and chemical degradation. Key to energising a new biofuel industry based on conversion of cellulose (and hemicelluloses) to ethanol is to understand plant cell-wall chemical and physical structures -- how they are synthesised and can be deconstructed. With this knowledge, innovative energy crops -- plants specifically designed for industrial processing to biofuel -- can be developed concurrently with new biology-based treatment and conversion methods. Recent advances in science and technological capabilities, especially those from the nascent discipline of systems biology, promise to accelerate and enhance this development. Resulting technologies will create a fundamentally new process and biorefinery paradigm that will enable an efficient and economic industry for converting plant biomass to liquid fuels. These key barriers and suggested research strategies to address them are described in this book. The core barrier is cellulosic-biomass recalcitrance to processing to ethanol. Biomass is composed of nature's most ready energy source, sugars, but they are locked in a complex polymer composite exquisitely created to resist biological and chemical degradation. Key to energising a new biofuel industry based on conversion of cellulose (and hemicelluloses) to ethanol is to understand plant cell-wall chemical and physical structures -- how they are synthesised and can be deconstructed. With this knowledge, innovative energy crops -- plants specifically designed for industrial processing to biofuel -- can be developed concurrently with new biology-based treatment and conversion methods. Recent advances in science and technological capabilities, especially those from the nascent discipline of systems biology, promise to accelerate and enhance this development. Resulting technologies will create a fundamentally new process and biorefinery paradigm that will enable an efficient and economic industry for converting plant biomass to liquid fuels. These key barriers and suggested research strategies to address them are described in this book.