In 1999 FIDIC introduced a new 'Red Book' for international civil engineering and large building projects, together with new Yellow, Silver and Green forms of contract for other types of project. However, the previous edition of the Red Book (the fourth edition) continues to be widely used and it seems likely that the 1999 edition will not replace it in the medium term, at least in certain parts of the world. This important work therefore continues to be based on the fourth edition of the Red Book and considers the many developments affecting the fourth edition that have taken place since 1997, when the second edition of this book was published, and relates them to key contracting issues. It also includes an important new section considering the 1999 Red, Yellow, Silver and Green forms and how they interact with the previous form.