2013

The cooperation on X-Road between Estonia and Finland officially started in 2013 when the Prime Ministers of Estonia and Finland, Andrus Ansip and Jyrki Katainen, signed the Memorandum of Understanding, initiating formal cooperation between the two states in respect of developing and maintaining a software environment enabling secure connectivity, searches and data transfers between various governmental and private databases – the X-Road®. This is considered to be the world’s first digitally signed international agreement.

The Parties decided to deepen the cooperation in a more formal yet flexible manner by forming a separate jointly managed special purpose organisation to administer the X-Road development – the Nordic Institute for Interoperability Solutions (NIIS).

2014–2016

The Population Register Centre of Finland (VRK) and the Information System Authority of Estonia (RIA) concluded a Cooperation Agreement intending to formalise the cooperation relating to X-Road and work as a contractual platform for deepening cooperation.

Finland's Population Register Centre and the Republic of Estonia's Information System Authority coordinated the X-Road core development. A set of practices and guidelines were agreed upon to manage the cooperation.

Another important outcome of the collaboration was publishing the source code of the X-Road core as open source under the MIT licence. The source code was published in two parts in 2015–2016, and it was made publicly available on GitHub.

2017–

NIIS history since 2017 is documented in the NIIS Yearbooks available at Publications.