Seldom has any business been in such turmoil as the Communication Service Providers (CSP) business is today. Telecom operators providing communication services constructed the infrastructure of the global information society with their trillion investments on various telecommunication technologies from broadband to mobile. Their investments on software turned their technology-specific in-house procedures into modern layered OSS/BSS. This book analyzes the status and the future evolution of OSS/BSS software industry from multiple viewpoints including technology diffusion, vertical disintegration and evolution of a vertical software industry. The analysis uses both commercial databases on software market transactions and interviews of operators in Europe and Far East, using quantitative and qualitative methods. This research complying academic standards aims at serving the practical business needs in the companies shaping the future of communications: the CSPs and the software developers sometimes found in a single enterprise.