ACKNOWLEDGMENTS This book is the result of over 40 years of invaluable collaboration and discussions with a long list of students and colleagues. It would have been impossible to write this book without the FactSage software and databases. I have collaborated with Chris Bale for 45 years and with Gunnar Eriksson for 40 years on the development of FactSage. I owe them an immense debt of gratitude. I am particularly indebted to my mentor Milton Blander for his inspiration and deep insights into the mysteries of the thermodynamics of solutions. Special thanks are due to Evguenia Sokolenko for her skillful and essential assistance in preparing the figures and formatting the text and equations. Finally, I wish to acknowledge the Natural Sciences and Engineering Research Council of Canada for financial assistance over many years.