With the arrival of new usages and stakeholders, the increase in fluctuating distributed energy resources, and the regulatory framework for grid operators, automation, monitoring and controllability are rising challenges for the distribution networks. The OpenNode project (www.opennode.eu), funded by the EU's Seventh Framework Programme (FP7/2007-2013) under the Grant Agreement Number 248119, brings together nine organizations from six European countries to tackle these issues. To address these topics, the OpenNode partners have developed an architecture combining smart metering with grid automation, which would allow today's power networks to evolve into smart distribution grids, enabling reliable and efficient grid operation. In order to elaborate this system, the OpenNode project has focused on the research and development of: (1) An open Secondary Substation Node (SSN), an essential control component of the future smart distribution grid; (2) A MiddleWare (MW) to couple the SSN operation with the utility systems for grid and utility operation; (3) A modular communication architecture based on standardised communication protocols.The paper describes the characteristics of the system and its benefits. We will go through the logic that led to the specification and implementation choices. The final assessment process will be detailed to provide an evaluation of the project's output.