Handbook of Truly Concurrent Process Algebra provides readers with a detailed and in-depth explanation of the algebra used for concurrent computing. This complete handbook is divided into five Parts: Algebraic Theory for Reversible Computing, Probabilistic Process Algebra for True Concurrency, Actors – A Process Algebra-Based Approach, Secure Process Algebra, and Verification of Patterns. The author demonstrates actor models which are captured using the following characteristics: Concurrency, Asynchrony, Uniqueness, Concentration, Communication Dependency, Abstraction, and Persistence. Every pattern is detailed according to a regular format to be understood and utilized easily, which includes introduction to a pattern and its verifications. Patterns of the vertical domains are also provided, including the domains of networked objects and resource management. To help readers develop and implement the software patterns scientifically, the pattern languages are also presented. Reversible computing is an interesting topic in Computer Science. Reversible computing has been used in many area, such as quantum computing, transactions in databases, and business transactions. In these application areas, there are two aspects of reversible computing: one is that there is a corresponding reverse atomic action for each atomic action, so it is reversible at the level of atomic action; the other is in program logic, for the forward logic is important and the reverse logic is important too. The relation between the forward logic and reverse logic is the main content of reversible computing.