The article describes the evolution of an innovative legal interoperability laboratory within the National School of Public Administration and Local Government in Athens, Greece. While critically analysing its general scope, objectives and structure, the knowledge management perspective of an interoperable legal informatics solution for handling big open legal data is brought into focus. In the context of the laboratory, the use of Legislation Editing Open Software (LEOS), a legal informatics tool that has been developed as a European Union ISA2 solution, is highlighted. Different aspects of and lessons learned from the training of public administrators are discussed while assessing this operations support system for potential use as a web-based authoring tool by the Hellenic public service. The evaluation of both the laboratory and the tool was conducted based on expert surveys, and possible upgrades are discussed to make the training of public administration more efficient.
