Some of the most promising, attention-getting energy alternatives aren't revolutionary ideas. We all know about windmills and waterwheels, which have been around for centuries. Today, a variety of improvements, including innovative turbine designs, are transforming these ancient machines into cutting-edge technologies that can help nations satisfy their energy needs. There's another old process -- one you probably don't know much about -- that's gaining in popularity and may join wind and hydropower in the pantheon of clean, renewable energy. The process is known as gasification. Gasification is a partial oxidation process whereby a carbon source such as coal, natural gas or biomass, is broken down into carbon monoxide (CO) and hydrogen (H2), plus carbon dioxide (CO2) and possibly hydrocarbon molecules such as methane (CH4). This is achieved by reacting the material at high temperatures (>700 C), without combustion, with a controlled amount of oxygen and/or steam. The resulting gas mixture is called syngas (from synthesis gas or synthetic gas) or producer gas and is itself a fuel. The power derived from gasification and combustion of the resultant gas is considered to be a source of renewable energy if the gasified compounds were obtained from biomass. Gasification is not a new technology; it was originally developed in the 1800s and is the processes used to make town gas for lighting and cooking. Small scale gasifiers were also used to power internal combustion engine vehicles during fuel shortages during the Second World War. If the gasification takes place at a relatively low temperature, such as 700C to 1000C, the product gas will have a relatively high level of hydrocarbons compared to high temperature gasification. As a result it may be used directly, to be burned for heat or electricity generation via a steam turbine or, with suitable gas clean up, to run an internal combustion engine for electricity generation. The book entitled Gasification for Practical Applications provides the practical information for researchers and graduate students who want to review the current situation, to upgrade, and to bring in a new idea to the conventional gasification technologies.