Ultimately, every theoretical mathematical machine' needs translation into a physical form, and this is what hardware is all about. The invention of hardware description languages (HDLs) in the early 1960s was an attempt to remain at an abstract level in the design process, pushing the stage of physical implementation to the point at which no more technology-independent decisions need to be made. It was also an answer to the continuous, exponential growth in the complexity of the systems to be designed. This complexity has meant that systems have become unmanageable in human terms, requiring CAD support. Furthermore, HDL descriptions remain implementation free', although increasingly precise and complete, meaning that the same system can undergo successive implementations over several technological generations. The first part of Fundamentals and Standards in Hardware Description Languages takes a look back over several decades, describing the mathematics, high level language concepts and system level methodology. This helps the reader to assimilate the theoretical background to the advanced application domains of HDLs, which are dealt with in the second part of the book. The third part provides a sampling of the most recent, fully implemented HDLs, demonstrating how new concepts can become a reality, how long it takes, and how long it will take to complete HDL up to the present level of knowledge.