To address the challenges for middleware emanating from the advent of the Internet of Things and cloud com- puting, new research is required, particularly with respect to the types of middleware needed to support key domains, such as cyber-physical systems, smart cities, the smart grid, big data analytics, digital earth, and so on. This special issue addresses these challenges by (i) considering the state- of-the-art of middleware in these areas, (ii) documenting emerging ideas and concepts that help meet key challenges, (iii) increasing awareness of a grand challenge for dis- tributed system, and (iv) galvanizing the community of researchers around this challenge