Book excerpt: Unconventional computing is a field of advanced computer science, which general goal might be summarised as the quest for both new groundbreaking algorithms and physical implementations of novel and ultimately more powerful - compared to classical approaches - computing paradigms and machines. This volume brings together work that especially focuses on experimental prototypes and genuine implementations of non-classical computing devices. A further goal was to revisit existing approaches in unconventional computing, to provide scientists and engineers with blue-prints of realisable computing devices, and to take a critical glance at the design of novel and emergent computing systems to point out failures and shortcomings of both theoretical and experimental approaches.