Open source software in the public sector: why it should be prioritised, what the legislation requires

Open source software is software whose source code is made available to the user and whose licence permits this code to be examined, modified, and redistributed. The most common criterion for whether a licence is considered open source is the Open Source Definition published by the Open Source Initiative (OSI). The definition consists of ten criteria. These include free redistribution, access to source code, permission for derivative works, no discrimination against persons or groups, and no restriction of the software to any field of use. According to the definition, the program must include the source code and must permit distribution in both source code and compiled form.

The Open Source Software Transition Analysis Guide, prepared by TÜBİTAK ULAKBİM and made available to institutions by the Digital Transformation Office, also defines an open source licence as a legal agreement containing the terms and conditions for the use, modification, and distribution of the software. The Guide also lists one by one the licences that can be accepted as open source for public institutions; Apache, MIT, BSD, GNU GPL, LGPL, AGPL, Mozilla Public License, and European Union Public Licence are included in this list.

The reasons for prioritising open source software come down to the question of who determines the institution's relationship with the software. In closed software, it is mostly the vendor that decides how the software will change, for how long it will be supported, and in what format the data can be extracted. In open source, a significant part of these decisions passes to the institution.

• Reduced vendor dependency: an institution with access to the source code and licence rights can have the software maintained and developed by different contractors without being tied to a single firm. The termination of a contract does not make it impossible to sustain the system.
• Auditability and security: because the source code can be examined, the institution, or independent experts it assigns, can directly review what the software does, what data it sends where, and possible security vulnerabilities. Open code alone does not provide security; it gains value together with regular updates and audits.
• Keeping data and the system within the institution: open source software can be run on the institution's own servers or on infrastructure of the institution's choosing. Data does not remain tied to a single vendor's service or closed format. In Europe this subject is addressed under the heading of digital sovereignty.
• Interoperability: software whose data structure and interfaces can be examined can be connected to other systems, and how data will be transferred in a future migration to another piece of software can be determined in advance.
• Cost: no per-user or per-device licence fee arises. The budget can be allocated to items directly tied to the institution's own needs, such as customisation, support, and training. The Circular also lists savings in information technology expenditure among the aims of the transition to open source.

Presidential Circular No. 2023/13 on the "Use of Open Source Software in the Public Sector," published in the Official Gazette dated 29 July 2023 and numbered 32263, sets its aim as expanding the use of open source software (AKKY) in the public sector in order to "save on information technology expenditure, reduce vendor dependency, and strengthen cyber security." Public administrations other than the institutions listed in the fields of defence, intelligence, and security — provincial special administrations, municipalities and their affiliated organisations, state economic enterprises, and revolving funds — fall within the scope of the Circular. The Circular contains four basic provisions:

• The "AKKY Transition Analysis and Roadmap Report," which shows the inventory of commercially licensed software in use and which of these can be replaced with AKKY equivalents, is prepared in accordance with the Digital Transformation Office's template and the Open Source Software Transition Analysis Guide, and is submitted to the Office within nine months.
• The financial resources and workforce required for the work covered by the report are allocated. The Presidency of Strategy and Budget takes these reports into account in information technology budget planning and appropriation allocation.
• In procurements of goods and services involving software supply, AKKY equivalents are preferred over commercially licensed software, except where this is not suitable for technical and/or economic reasons. Where AKKY is not preferred, the justification is explained in detail in the project proposal forms.
• Software developed through the customisation of existing AKKY by firms operating in Turkey, using personnel employed in Turkey, is also considered in the transition process; where no suitable AKKY product is available, it is preferred over commercially licensed software.

The Guide groups the transition analysis into four sections: inventory study, technical analysis, competency analysis, and cost analysis. In the technical analysis, the relationships and dependencies of existing software with other systems are examined; professional applications such as mapping and drawing applications are also included in this scope. Software planned to be purchased in the near future is expected to be included in the analysis, and the extent to which requirements can be met by open source alternatives is expected to be assessed. The Guide directs the search for equivalent software to the list of open source software on TÜBİTAK ULAKBİM's Pardus website. The Pardus operating system, based on Debian GNU/Linux, is developed within TÜBİTAK.

According to Article 5 of the Public Procurement Law No. 4734, administrations are responsible for ensuring transparency, competition, equal treatment, reliability, confidentiality, public oversight, the timely fulfilment of needs on suitable terms, and the efficient use of resources in procurements. Article 12 of the same Law requires that technical criteria be aimed at ensuring efficiency and functionality, contain no elements that hinder competition, and provide equal opportunity for all bidders.

Article 12 further stipulates that technical specifications may not specify a particular brand, model, patent, origin, source, or product, and may not include features or descriptions directed at a particular brand or model. Where national and/or international technical standards do not exist, or where technical characteristics cannot be determined, a brand or model may be specified, but only on condition that the phrase "or equivalent" is included. Read together with the Circular, this provision requires that the specification be written in terms of the function the software must perform, the open standards it must support, and the format in which data is to be delivered, rather than in terms of a particular product.

The European Commission approved its 2020-2023 Open Source Software Strategy, titled "Think Open," on 21 October 2020. The strategy is based on the principles of open thinking, transformation, sharing, contribution, security, and retaining control, and lists contribution to Europe's digital autonomy among its goals. The Interoperable Europe Act (Regulation (EU) 2024/903), which entered into force on 11 April 2024, introduces tools such as mandatory interoperability assessments measuring the impact of changes in information systems, and the sharing and reuse of interoperability solutions through a portal.

Germany's state of Schleswig-Holstein is carrying out a comprehensive transition that is moving the standard working environment in public administration to open source. According to the state government's statement, updated in December 2025, LibreOffice is used as office software on approximately 80 percent of workstations outside the tax administration, and approximately 44,000 e-mail accounts have been migrated to Open-Xchange. The state states that this transition has achieved savings of more than 15 million euros per year in licence expenditure, while a one-off investment of 9 million euros is required for 2026 for transition and development purposes. The statement expresses the aim as reducing technical, and therefore economic, dependency on individual vendors. In France, meanwhile, the state has since 2013 collected the free software it recommends in a list called SILL (Socle interministériel de logiciels libres).

These examples show that the transition to open source is not limited to a one-off product change; it requires an inventory, investment, training, and a roadmap spread over several years. The analysis and roadmap report required by the Circular in Turkey rests on the same logic. The next article in the series addresses licence types and the institution's obligations.