Guide for Using Open Source Software

The Directive on Management of Information Technology, Appendix C provides Mandatory Procedures for Enterprise Architecture Assessment, that will be used by departmental Architecture Review Boards (ARB) and the Government of Canada Enterprise ARB as an assessment framework to review digital initiatives to ensure the GC acts as a single enterprise and to ensure departmental alignment with the GC digital direction.

These align with the Digital Standards and requirement C.2.3.8 of the Mandatory Procedures for Architecture Assessment which provide that, where possible, open source software be used first.

The steps for GC to use open source software are:

  1. Actively and Fairly Consider Open Source Software
  2. Verify Open Source Software Ownership or Licence
  3. Evaluate Support Options
  4. Use Open Source Software Without Modification
  5. Use Open Source Software With Modifications
  6. Register to Open Resource Exchange

Actively and Fairly Consider Open Source Software

Be aware that open source software is not completely free, so take into account the total cost of ownership (TCO) of migrating, including exit, transition, and support costs.

Be Aware of Open Core

A solution that is built with open source software but requires the use of closed-source components should not be considered open source software for the purpose of this guide. The open core development model is where vendors open only portions of their software and then surround the remainder with closed-source offerings, as well as the model where a user such as Canada augments already licenced proprietary software with open source software. The “free” open source software versions often referred to as “community” editions are recommended first. See Verify Open Source Software Ownership or Licence.

Selecting Open Source Software First

The mandatory procedures for enterprise architecture assessment ( see annex C of the Directive on Management of Information Technology ) require application architecture – for both new technology and upgrade/migration of existing solutions – to prioritize the use of open source software as well as open standards. Doing so maximizes the substitutability and interoperability of software components and opens the door to creating highly flexible solutions. It also helps mitigate the significant risks which arise from lock-in and similar issues.

Sometimes an open source solution meets most user needs but would require additional investment to develop missing functionality (see Guide for Contributing to Open Source Software). In these cases, this investment must be considered by weighing the total cost of ownership against those of other candidate solutions.


The same factors applicable to an evaluation of the feature set and maturity of closed-source software also apply to open source software. Additional criteria should be assessed when evaluating open source software:

1. User Community

A strong user community involved in a project provides people to answer questions, test the software, report bugs, suggest improvements and drive forward overall interest in the software. Look at the software’s public code repository and check the project popularity by looking at the number of likes and followers. Check how active the project responds to users by looking at issues and the time between replies.

2. Developer Community

A strong developer community with a history of releases and continued involvement tends to demonstrate that fixes and improvements to the software will continue into the future. Look at who are the core developers and who is supporting the project and community, such as a non-profit Foundation. Look at when the project got started, the pace of releases and responses to requests to merge code from contributors.

3. Documentation

User documentation provides important information to help users install software and use its features. Technical documentation provides requirements and instructions for installation, development, deployment and configuration of the software.

4. Security Assessments

Although OSS code is auditable, this does not necessarily mean it is secure. The quality of the code and the typical response time for patching security-related flaws help indicate the security maturity level of the software.

As per any software, you should maintain best practices and have a process in place to list all packages in use as well as their version in order to patch them promptly.

Verify Open Source Software Ownership or Licence

Whenever the Crown is contemplating acquiring software under an open source licence, departments should review the terms and conditions to validate if they can accept and comply with them given their particular business context.

The software is usually provided ‘as-is’ meaning the community will not accept liability or provide any financial compensation to the Crown for service interruption, loss of data, or loss of confidentiality. As such, you should consider the software obtained under an OSS licence with the same responsibility lenses as if you had written it.

All software licensed under an Open Source Initiative approved license or a Free Software Foundation free software licence is considered open source software and, where its use is possible in accordance with this Guide, can be used by the GC without modifications.

However if the software needs to be modified, the following considerations should be discussed with the appropriate stakeholders (i.e end users, project managers, legal services) and applied to help identify what licences terms and conditions the department is willing to approve.

  1. Are there any reasons that would prevent the release of the modified source code?
  2. Is the modified application going to be used as a web application?
    • Yes: Subject to the considerations above, you can accept any OSI approved licence or FSF free software licence except strong reciprocal licences. See Strong Reciprocal Licences.
    • No: See 3.
  3. Is the modified application going to be distributed externally, outside the GC, either the source code or the binary?
    • No: Subject to the considerations above, you can accept any OSI approved licence or FSF free software licence.
    • Yes: Subject to the considerations above, you can accept any OSI approved licence or FSF free software licence except Reciprocal Licences. Use only Permissive Licences.

Additional consultation with legal and engineering teams should be done for scenarios where the open source software is used as a component of custom development (e.g.: dynamic vs static linking, etc.) to ensure licence compatibility.

Popular and Widely Used Licences

The following are lists of licences categorized by permissive and reciprocal. For full list refer to Open Source Initiative (OSI) and Free Software Foundation (FSF) Websites.

Permissive Licences

  • Apache License
  • BSD license
  • ISC License
  • MIT license

Reciprocal Licences

  • Eclipse Public License (EPL)
  • European Union Public License (EUPL)
  • GNU General Public Licenses (GPL, LGPL and AGPL)
  • Mozilla Public License (MPL)
  • Open Software License (OSL)

Evaluate Support Options

Use of open source software introduces a different model based on support services rather than obtaining software licences.

The two major support models for open source software are self-support, where the department or agency’s internal IT team is responsible for maintenance and interacting with the community, or professional support.


Using a self-support model requires that the responsible teams:

  • Have a proper process in place to manage the evaluation and the introduction of open source software in the organization.
  • Maintain and track thorough lists of all software used how and by whom.
  • Ensure updates are applied in a timely fashion.

User and developer community should be leveraged for general support questions as well as reporting bugs, creating feature requests and code contributions.

When using software components for development purposes, powerful tools and services can be leveraged by IT teams to automate, facilitate and speed up the identification of these components, including open source software. These tools can provide scanning capabilities for known security vulnerabilities as well as legal compliance.

See Guide for Contributing to Open Source Software.

Professional Services

It is possible to enter in contract with a company for professional services to provide maintenance, updates, warranty and liability for open source software.

Another scenario that may become recurrent would be choosing an open source software and using the community version and later down the road going for tender for professional support and maintenance.

When custom development requires the use of contracted developers, ensure that the proper rights to the source code are obtained to release as open source in accordance with the Guide for Publishing Open Source Code.

Use Open Source Software Without Modification

Using open source software without modification does not require that code be shared back.

Configuration of software, even through configuration files, are not considered modifications.

This is also true for combinations of open source software to build a solution or open source software used for development and deployment. See examples below:


Web browser, Productivity suite, Operating system and utilities (Window manager, Desktop environment, Text editor, Console..), ..

Combination of components

Application and plugins with database and web server

Development and deployment

Custom development using open source software programming languages and dependencies, HTTP server, Database management system, Container platform


For development or when writing source code, see Guide for Publishing Open Source Code.

Use Open Source Software With Modifications

Using open source software with modifications is not generally considered distribution and does not require that code be shared back.

Modifications made to open source software should still be shared with the community to help ensure sustainability of the solution. See Guide for Contributing to Open Source Software.

For cases where sharing modifications is mandatory, see Strong Reciprocal Implications.

Don’t Fork Open Source Software

Wherever possible, use open source software without modification or contribute back to the project.

Use configuration and customize the software with modules, plugins or extensions and make those available to the community. See Guide for Publishing Open Source Code.

It’s easy to copy (fork) open source software and start making changes to the source code. If a literal fork is created, which means taking a copy of the source code and maintaining your own version independently from the original project, be aware it can make future updates and security patches hard to implement. The development team that made the changes will be responsible for maintaining those changes indefinitely unless they are contributed to the upstream version, which is the original project from which the source code was taken.

To make changes to open source software, engage with the community and submit changes upstream to ensure that they are supported by future updates. See Guide for Contributing to Open Source Software.

Note: the term “fork” in the literal sense may be confused with the process of forking (cloning) projects on GitHub, GitLab and Bitbucket, which is critical to submit changes back to the original project.

Strong Reciprocal Implications

Strong reciprocal licences consider that software accessed through a network (like the Internet) is distribution and the modified source code must be made available to users. See Guides for Publishing Open Source Code and Contributing to Open Source Software.

Strong Reciprocal Licences

The Open Source Initiative approved licenses and the Free Software Foundation free software licences contain the following strong reciprocal licences.

  • GNU Affero General Public License (AGPL)
  • European Union Public License (EUPL)
  • Open Software License (OSL)

Register to Open Resource Exchange

Departments are encouraged to add all open source software your department or agency is using to the Open Source Software section on the Open Resource Exchange.

The goal of this platform is to help find other departments that have successfully used open source software as part of the production environment and create ties with the open source communities around them.

This is also in line with the Digital Standard: Work in the Open by default.

Instructions on how to update the data can be found on GitHub.

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