The following organizations have participated in the core development of X-Road:

• AA Arendus OÜ

• AS Aetec (later Profit Software OÜ)

• OÜ Aktors – core development

• AS Andmevara* – test queries to the population register, Estonian Registry of Buildings

• ASA Quality – core development related testing 2015, 2017, 2018

• AS Assert (later AS Cell Network; AS Fujitsu Estonia; OÜ Aktors) – winner of the first public procurement in 2001; subcontractors marked with *

• BCS (later AS CGI Eesti) – specifications for the public procurement of 2001

• Cybercom Finland Oy – product owner role at the Finnish side in the joint core development by Estonia and Finland

• Cybernetica AS* – architecture, protocols and security solutions, core development 2001–2018

• Datel AS* – test queries to electronic Land Register; core development related testing 2017

• Estonian commercial banks* – authentication of users

• Futurist Estonia

• Gofore Oyj – core development 2015–2022

• IBM – specifications for the public procurement of 2001

• OÜ IT Meedia

• Itera (later AS BCS Itera) – specifications for the public procurement of 2001

• Meliorad OÜ

• AS MicroLink – specifications for the public procurement of 2001

• NOPE Creative

• Nordic Institute for Interoperability Solutions (NIIS) – responsibility for core development 2018–

• Nortal – core development 2022–

• Opin Kerfi - open source contributions

• Q-Factory – core development related testing 2015 –

• AS Reaalsüsteemid* – test queries to Commercial Register

• Roksnet – open source contributions

• AS Softshark (later TietoEnator Financial Solutions AS; Tieto Estonia AS) – specifications for the public procurement of 2001

• Stockholm Environment Institute (SEI)

• Trinidad Wiseman