The European Commission has announced a plan to build an agile suite of pan-European public services through the loose integration of computer systems in every public authority of all 27 countries in the European Union, using a policy of open standards and open data.

The European public data mash-up would operate on an immense scale and would lead to the ambitious modularisation of European public services and computer systems, creating something akin to a pan-European G-Cloud and a "pick 'n' mix" menu of shared services.

The Commission delighted open systems campaigners who feared that powerful software companies would block any attempt to impose open standards over their own proprietary tools for data communications and systems interoperation.

The European Interoperability Strategy introduced by Commission Vice-President Maroš Šefčovič, promises to build the technical foundations for greater European integration, a more effective single market and the radical introduction of pan-European public services built as an amalgam of national resources.

At the centre of the plan was the interoperability not just of public computer systems but of public services.

European businesses and citizens could not co-operate "without real, effective interoperability between public administrations at all levels" said Šefčovič in a statement.

The Commission warned European member states against putting up "electronic barriers" between one another, as would happen if they failed to ensure their computer systems could communicate and share data readily.

The plan augmented the European Union's law of attraction - that the European project would lead inevitably to closer integration - with another gravitational force: that of computer networks and the internet, which had produced an even more irresistible imperative for sharing resources.

The glue above it all would be a system of "semantic interoperability", akin to web founder Sir Tim Berners-Lee's semantic web - a project "never attempted on this scale" by which member states would find common ways of identifying and giving meaning to data they shared.

The underlying principle, defined yesterday with the publication of the long-awaited European Interoperability Framework, was "technological neutrality and adaptability".

It amounted to an open data policy for Europe, and a commitment to use open standards where they existed and they met the needs of the public authorities that were deploying them.

Veteran software campaigner Florian Mueller said on his blog: "I am delighted to see that the Commission adopted a pragmatic and inclusive definition of open standards."

The Commission had settled the controversial differences between free software campaigners and patent holders in a way that was "absolutely consistent" with the middle-ground.

The plan encouraged member states to get involved in standard-setting, assisting them with definitions of interoperability and open standards that Mueller said united the two warring software factions.

Graham Taylor, director of open source lobby group Open Forum Europe, said: "It's a lot better than we feared. They managed to do what they set out to achieve with the essence of openness and the avoidance of vendor lock-in. But it lacks detail."