There is almost no field in mathematics that does not use mathematical analysis. Computer methods in applied mathematics are often based on statements and procedures of mathematical analysis as well. An important part of mathematical analysis is complex analysis because it has many applications in various branches of math. Present trends in complex analysis, which are reflected in this book, are mainly concentrated on the following four research directions: value distribution theory and its applications; holomorphic functions in several (finitely or infinitely many) complex variables; Clifford analysis, (complex methods in higher-dimensional real Euclidian spaces); and generalized analytic functions. A specific feature of contemporary complex analysis is combining methods of Clifford analysis. This leads to a theory of multi-regular functions.