The 7 revised papers presented together with an invited paper were carefully reviewed and selected from 9 submissions. The contributed presentations covered a range of topics about the algebraic approach to system specification, which encompasses many aspects of the formal design of software systems. Originally born as formal method for reasoning about abstract data types, the algebraic approach now covers new specification frameworks and programming paradigms (such as object-oriented, aspect-oriented, agent-oriented, logic, and higher-order functional programming) as well as a wide range of application areas (including information systems, concurrent, distributed, and mobile systems).