th The 20 anniversary of the IFIP WG6. 1 Joint International Conference on Fonna! Methods for Distributed Systems and Communication Protocols (FORTE XIII / PSTV XX) was celebrated by the year 2000 edition of the Conference, which was held for the first time in Italy, at Pisa, October 10-13, 2000. In devising the subtitle for this special edition --'Fonna! Methods Implementation Under Test' --we wanted to convey two main concepts that, in our opinion, are reflected in the contents of this book. First, the early, pioneering phases in the development of Formal Methods (FM's), with their conflicts between evangelistic and agnostic attitudes, with their over optimistic applications to toy examples and over-skeptical views about scalability to industrial cases, with their misconceptions and myths . . . , all this is essentially over. Many FM's have successfully reached their maturity, having been 'implemented' into concrete development practice: a number of papers in this book report about successful experiences in specifYing and verifYing real distributed systems and protocols. Second, one of the several myths about FM's - the fact that their adoption would eventually eliminate the need for testing - is still quite far from becoming a reality, and, again, this book indicates that testing theory and applications are still remarkably healthy. A total of 63 papers have been submitted to FORTEIPSTV 2000, out of which the Programme Committee has selected 22 for presentation at the Conference and inclusion in the Proceedings.

LOTOS (Language Of Temporal Ordering Specification) became an international standard in 1989, although application of preliminary versions of the language to communication services and protocols of the ISO/OSI family dates back to 1984. This history of the use of LOTOS made it apparent that more advantages than the pure production of standard reference documents were to be expected from the use of such formal description techniques. LOTOSphere: Software Development with LOTOS describes in depth a five year project that moved LOTOS out of the ISO tower into software engineering practice. LOTOS became a vehicle for efficient, yet formally based industrial software specification, design, verification, implementation and testing. LOTOSphere: Software Development with LOTOS is divided into six parts. The first introduces the reader to LOTOS and the project LOTOSphere. The five remaining each treat an important part of the software development life cycle using LOTOS. This is the first book to give a comprehensive treatment of the use of these formal description techniques in a software engineering environment. It will thus be a valuable reference for researchers and software developers and can also be used as a text for an advanced course on the subject.

th The 20 anniversary of the IFIP WG6. 1 Joint International Conference on Fonna! Methods for Distributed Systems and Communication Protocols (FORTE XIII / PSTV XX) was celebrated by the year 2000 edition of the Conference, which was held for the first time in Italy, at Pisa, October 10-13, 2000. In devising the subtitle for this special edition --'Fonna! Methods Implementation Under Test' --we wanted to convey two main concepts that, in our opinion, are reflected in the contents of this book. First, the early, pioneering phases in the development of Formal Methods (FM's), with their conflicts between evangelistic and agnostic attitudes, with their over optimistic applications to toy examples and over-skeptical views about scalability to industrial cases, with their misconceptions and myths . . . , all this is essentially over. Many FM's have successfully reached their maturity, having been 'implemented' into concrete development practice: a number of papers in this book report about successful experiences in specifYing and verifYing real distributed systems and protocols. Second, one of the several myths about FM's - the fact that their adoption would eventually eliminate the need for testing - is still quite far from becoming a reality, and, again, this book indicates that testing theory and applications are still remarkably healthy. A total of 63 papers have been submitted to FORTEIPSTV 2000, out of which the Programme Committee has selected 22 for presentation at the Conference and inclusion in the Proceedings.

LOTOS (Language Of Temporal Ordering Specification) became an international standard in 1989, although application of preliminary versions of the language to communication services and protocols of the ISO/OSI family dates back to 1984. This history of the use of LOTOS made it apparent that more advantages than the pure production of standard reference documents were to be expected from the use of such formal description techniques. LOTOSphere: Software Development with LOTOS describes in depth a five year project that moved LOTOS out of the ISO tower into software engineering practice. LOTOS became a vehicle for efficient, yet formally based industrial software specification, design, verification, implementation and testing. LOTOSphere: Software Development with LOTOS is divided into six parts. The first introduces the reader to LOTOS and the project LOTOSphere. The five remaining each treat an important part of the software development life cycle using LOTOS. This is the first book to give a comprehensive treatment of the use of these formal description techniques in a software engineering environment. It will thus be a valuable reference for researchers and software developers and can also be used as a text for an advanced course on the subject.