Cyber-Physical Systems (CPS) are integrations of computation and physical processes. This kind of systems is being increasingly used in different domains such as healthcare, transportation, process control, manufacturing or electric power grids. CPS interact with the physical world and must operate dependably, safely, securely, efficiently and, frequently, in real-time. Consequently, they require new computing and networking technologies capable of supporting them adequately in environments qualitatively different from those found in general purpose computing. This paper analyzes the applicability of different middleware technologies as data distribution means for CPS.