Open source software (OSS) has become the bedrock for the majority of software applications – from smartphones to space shuttles. Characterized by the accessibility of its source code to the public, OSS typically enables unrestricted viewing, usage, modification, and distribution of the source code.

The surge in the adoption of OSS is a noteworthy trend across various industries. Organizations are increasingly drawn to the benefits it offers, including cost-effectiveness, flexibility, and the innovative power derived from a collaborative, community-driven approach – even if maintainers are still agonizingly underpaid. 

But as the owners of this software increasingly clamp down on permissive licenses, and bigger security holes open up, engineering leaders need to proceed with caution when adopting open source software. Here are 12 areas to consider before bringing a piece of open source software into your codebase.

1. Licensing

For the uninitiated, the world of open source software licenses can be intimidating. Let's start with the fundamentals of understanding the legal framework governing the use and distribution of open source software. This section provides an exploration of various types of licenses, including but not limited to: MIT, GPL, and Apache licenses. Each license type carries its own set of permissions and restrictions, influencing how the software can be used and shared.

These licenses are also liable to change, as the owner decides how permissive they want to be and how they want to monetize the software. Take Hashicorp, which announced in August 2023 that it was moving its popular infrastructure-as-code Terraform tool from a Mozilla Public License v2.0 (MPL 2.0) to the less open Business Source License (BSL) v1.1. This license type was largely created to fend off the threat of cloud providers reselling open source software for profit. The Terraform community immediately announced an OpenTF fork, aimed at allowing end users their usual free reign over usage of the code.

“There are other vendors who take advantage of pure OSS models, and the community work on OSS projects, for their own commercial goals, without providing material contributions back,” wrote HashiCorp cofounder and CTO Armon Dadgar at the time. “We don’t believe this is in the spirit of open source. As a result, we believe commercial open source models need to evolve for the ecosystem to continue providing open, freely available software.”

Types of Licenses

Different open source licenses exist, each with unique characteristics. Examples include the permissive MIT License, the copyleft-oriented GPL (General Public License), and the business-friendly Apache License, which allows for limitless reuse without fear of patent infringement and is broadly compatible with a variety of proprietary software.

Understanding these licenses is essential for developers and project contributors to align their work with the intended usage and distribution policies. 

“Architects who use open source will see many more custom licenses that call themselves open source but have stipulations that require legal approval, and more companies will threaten to drop customers who request the source to which they’re entitled,” Forrester analyst Chris Gardner wrote in October 2023.

Choosing the right license for your project

Selecting an appropriate license is a critical decision in the development of open source projects. This involves considering factors such as project goals, collaboration preferences, and desired levels of control over derivative works. 

By strategically choosing a license, project maintainers can establish the framework for how their software is shared and reused within the community.

License compatibility and potential conflicts

Ensuring compatibility between licenses is crucial when integrating or combining different open source components.

• Dual licensing

Dual licensing is a strategic approach employed by open source projects to offer users more flexibility in how they can use, modify, and distribute the software. In this model, the project maintainers provide the option for users to choose between two or more licenses. Each license may have different terms, allowing users to select the one that aligns best with their specific requirements or business constraints.

Dual licensing allows projects to cater to a broader user base, including both commercial and non-commercial users, by offering licenses that suit different use cases. It provides potential revenue streams for projects, especially when commercial entities may choose a different license that requires a payment for proprietary usage.

Communicating dual licensing transparently is crucial to avoid confusion among contributors and users. Managing contributions under different licenses can be complex, requiring clear guidelines and contributor agreements.

• License enforcement and legal implications

Ensuring license compliance is vital to maintain the open and collaborative nature of open source projects. This involves monitoring and enforcing the terms of the chosen licenses to address potential violations. Legal implications can arise if license terms are not adhered to, such as cease and desist orders or monetary damages. License violations can lead to a loss of trust within the community, impacting the project’s reputation and collaboration.

Projects often rely on a combination of community vigilance, automated tools, and legal actions to enforce license compliance. Some projects use a license file with clear instructions and requirements for usage, distribution, and modification, making it legally binding.

Regular audits and scans of project dependencies help identify potential license violations. Clear communication channels, such as issue trackers or dedicated mailing lists, allow the community to report and address license-related concerns promptly.

2. Community support

Beyond sheer numbers, a thriving community nurtures collaboration, sparks innovation, and instills a collective sense of ownership, thereby bolstering the project’s efficacy and ensuring its enduring presence.

To gauge the health of an open source community in a more nuanced manner, it is imperative to delve into specific technical details and key performance indicators. When considering community size and activity, tracking metrics such as the number of active contributors, both individual and organizational, within public version control systems like GitHub and issue trackers like Jira becomes crucial.

Additionally, assessing the diversity of contributors based on factors like geographical location and affiliation provides valuable insights. Evaluating activity involves monitoring commit frequency, code contributions, and engagement metrics on communication platforms like mailing lists or forums.

Managing issues efficiently is a cornerstone of a healthy community. Metrics such as the average response time to newly opened issues and the resolution time for issues offer quantifiable insights. For pull requests, evaluating the time taken for community review and merging, along with the percentage of pull requests receiving timely responses, becomes pivotal.

Examining communication channels like mailing lists, forums, and chat platforms requires a nuanced approach. For mailing lists and forums, the frequency and depth of discussions, coupled with the diversity of topics, reflect the community’s engagement levels. 

On chat platforms, assessing the responsiveness of community members and the inclusivity of discussions provides a real-time perspective.

3. Security

Ensuring the security of open source software is imperative in the contemporary digital landscape. Regular code audits and reviews constitute a fundamental security assessment, requiring a systematic examination of the source code by developers and security experts.

The objective is to proactively identify and rectify potential security flaws, ultimately reinforcing the overall integrity of the software. Swiftly addressing vulnerabilities is equally critical for maintaining a secure open source ecosystem. Effective strategies, including timely patching, play a central role, with best practices emphasizing transparent communication within the community and collaborative efforts to swiftly mitigate potential risks.

Understanding and fortifying your software supply chain are also paramount for mitigating risks associated with dependencies and external sources. Dependency scanning can help identify and address potential security vulnerabilities. 

This practice ensures that integrated software components remain free from known vulnerabilities, contributing to the project’s overall security posture and minimizing risks linked to dependencies. Establishing trust in software sources is foundational to mitigating the risk of malicious or compromised components infiltrating the software supply chain. 

Verification methods include checking digital signatures, relying on reputable package managers, and actively participating in community efforts. These measures collectively enhance the security and trustworthiness of the software supply chain, fortifying open source projects against potential security threats, like the high profile Log4j vulnerability of 2021. 

This exposed a critical security flaw in the widely used Apache Log4j library, underscoring the potential hazards associated with depending on third-party open source components, as vulnerabilities in widely adopted libraries can have a widespread impact. It also exemplified the collaborative nature of the open source model, as unpaid maintainers swiftly mobilized to address vulnerabilities and release patched versions.

4. Documentation

Comprehensive documentation is fundamental to  the success of open source projects, playing a crucial role in facilitating understanding, adoption, and contribution to the software. Documentation enhances accessibility, ease of use, and collaboration, ultimately contributing to the overall success and sustainability of the project.

Quality documentation extends beyond its mere existence. It must be clear, relevant, and easily accessible. When evaluating the quality of documentation, specific considerations come into play:

• Availability of documentation

The availability of documentation is the initial step in enabling users and contributors to comprehend a project. This aspect explores the critical nature of accessible documentation, ensuring it is readily available and easily discoverable. Whether presented as online guides, wikis, or integrated help systems, accessible documentation is essential for users of all proficiency levels.

• Clarity and relevance

Effective documentation is characterized by its clarity and relevance. Documentation should be up-to-date, reflecting the current state of the project, and presented in a manner that is easy to comprehend. Prioritizing clarity and relevance not only enhances the user experience, but also reduces entry barriers and cultivates a more inclusive and collaborative open source community.

5. Code quality

Integral to the sustained success of open source projects is the effective maintenance of code. Key considerations for evaluating a project’s codebase maintenance include the frequency of code updates. 

The responsiveness of the development team to evolving requirements and potential issues is reflected in regular updates, addressing bugs, introducing features, and ensuring project stability. Such frequent updates signal an active and engaged development community, contributing to code reliability, and user satisfaction.

Understanding and assessing code complexity are fundamental aspects of evaluating code maintenance. Exploring specific metrics like cyclomatic complexity, which represents the number of linearly independent paths through a program's source code, and maintainability index, which is a composite metric that combines cyclomatic complexity, lines of code, and comments to provide a score representing how maintainable the code is. These metrics will provide valuable insights into overall code complexity. 

Monitoring these metrics empowers project maintainers to make informed decisions about refactoring, optimization, and overall codebase improvement. A well-structured codebase with an appropriate level of simplicity not only facilitates contributions but also minimizes the likelihood of errors. 

This comprehensive understanding of the technical intricacies involved in code quality and maintenance establishes a solid foundation for nurturing a robust and high-quality codebase in open source projects.

6. Compatibility and interoperability

Compatibility with other software is a critical aspect with open source projects, emphasizing the need for seamless integration with diverse tools and systems. 

Make sure you have assessed the software’s interoperability, especially concerning established systems. Look out for conflicts in dependencies, disparities in data formats, or variations in protocols.

7. Governance and project leadership

Open source projects operate under a variety of project governance models, influencing decision-making processes, community engagement, and overall project direction. The distinction between centralized and distributed governance structures shapes the dynamics of the project, impacting its adaptability and capacity to thrive in the open source ecosystem.

Key considerations in this evaluation include examining the decision-making processes employed by project leadership. Transparency and inclusivity in decision-making, encompassing consensus-building, community input mechanisms, and the role of project maintainers, all play a pivotal role in fostering a collaborative environment.

Furthermore, ensuring the long-term viability of an open source project necessitates a thorough evaluation of the stability and foresight demonstrated by its leadership. This evaluation delves into factors such as strategic planning, resource management practices, and continuity planning.

8. Long-term support

Effective long-term maintenance stands as a cornerstone for the enduring success of open source projects. A deep dive into the significance of establishing clear and robust long-term maintenance plans reveals the necessity of ensuring continuous support, updates, and bug fixes. This underscores the importance of a proactive approach to address evolving user needs and potential challenges.

When evaluating an open source project, a critical aspect involves examining its track record, providing valuable insights into stability and reliability over time. This evaluation encompasses the project’s performance in terms of reliability, bug resolution, and overall consistency. A project’s track record of stability significantly contributes to user trust and confidence, reflecting a commitment to quality and fostering long-term relationships with users and contributors.

Additionally, understanding how a project has managed major releases and upgrades in the past is crucial for anticipating its future evolution. This exploration delves into considerations such as the frequency of major releases, the impact on existing users, and the efficacy of the upgrade process. Projects that have adeptly handled significant updates showcase a dedication to innovation and adaptation, crucial elements for ensuring their long-term viability in open source development.

9. Scalability

A big challenge for open source projects is how they scale to serve larger user bases. As open source projects gain popularity, the demand on infrastructure and services escalates, requiring effective strategies to handle heightened user loads. 

Performance concerns become paramount as a project expands. Scalability involves not only accommodating more users but also maintaining optimal performance levels. This includes addressing issues related to response times, data processing, and overall system efficiency.

• Project architecture

The cornerstone of scalability lies in a well-designed and adaptable project architecture. This involves structuring code in a modular and flexible manner, anticipating evolving requirements, and utilizing technologies that inherently support scalability. Scalable project architectures can seamlessly adapt to the changing demands of a growing project, ensuring a smooth and efficient development process.

• Community and infrastructure scalability

Scalability extends beyond code to encompass community engagement and infrastructure. Attracting and retaining contributors and users is crucial for community scalability. Effective strategies involve fostering a welcoming environment, providing clear documentation, and encouraging collaboration. Infrastructure scalability includes considerations such as server capacity, deployment processes, and the ability to handle increased traffic. 

Robust infrastructure ensures the project can cope with expanding user bases and evolving technical demands, contributing to the overall resilience and success of open source projects.

10. Compliance

In the intricate landscape of open source projects, the foundation for ethical and lawful operations rests upon meticulous adherence to legal and regulatory compliance. Mitigating legal risks hinges on meticulous compliance with open source licenses. 

Understanding and adhering to the terms of the chosen license is paramount. This involves implementing best practices in license management, tracking dependencies, and promptly addressing any licensing issues that may arise. Such diligence not only upholds the integrity of the project, but also fosters a transparent and legally sound environment for contributors.

Open source projects, with their global user and contributor base, necessitate a nuanced approach to international legal considerations. Guidance is provided on navigating these legal complexities across different regions, ensuring the project remains compliant. 

Heightened awareness of and responsiveness to international considerations not only expand the project’s global reach but also proactively mitigates potential legal entanglements. Compliance with legal and regulatory requirements is not merely a safeguard; it is a cornerstone for fostering a trustworthy, responsible, and sustainable open source ecosystem.

11. Community values and culture

The core values of an open source project serve as its moral compass, guiding the development, decision-making, and collaborative interactions within the community. 

These values typically encompass principles such as transparency, inclusivity, openness, and the pursuit of shared goals. For example, if transparency is a core value, the project may prioritize open communication channels, decision-making processes, and public documentation. 

• Codes of conduct

Codes of conduct are explicit guidelines that set behavioral expectations for all community members. They play a crucial role in fostering an inclusive and respectful environment. A well-structured code of conduct outlines acceptable behavior, mechanisms for reporting violations, and a fair resolution process. 

Emphasizing inclusivity, it actively works to prevent discrimination, harassment, and any form of exclusionary practices. An effective code of conduct is a proactive measure to create a safe space for contributors from diverse backgrounds, ensuring everyone feels welcome and valued.

• Contributor guidelines

Contributor guidelines are practical documents that provide guidance on how individuals can contribute effectively to the project. In the context of fostering inclusivity and diversity, these guidelines address onboarding processes, communication norms, and strategies to support contributors from various backgrounds. 

Clear contributor guidelines streamline the onboarding experience, reducing barriers to entry for newcomers. They may also emphasize mentorship programs, recognition of diverse contributions, and measures to ensure equitable opportunities for involvement.

This approach attracts a broad range of contributors, fostering creativity, innovation, and long-term success within the project. It also promotes a positive reputation, making the project more appealing to potential contributors and users alike.

12. Exit strategy

When adopting open source software, it’s important to recognize the need to proactively prepare for unforeseen events. Establishing a robust exit strategy is imperative to navigate unexpected challenges or shifts in project direction. 

This involves anticipating potential scenarios, such as key contributors leaving, changes in technology landscapes, or shifts in project priorities. A comprehensive exit strategy ensures that the project remains adaptable and responsive to the dynamic nature of the open source ecosystem.

Mitigating risks and ensuring continuity form the crux of a well-defined exit strategy, offering a structured approach to handle unexpected developments.

• Transitioning to alternatives

In the event of unforeseen circumstances, having a strategic plan for transitioning to alternatives is critical. This involves not only technical considerations, but also effective communication and collaboration. Strategies for transitioning users, contributors, and maintainers to alternative solutions or forks should be explored. Clear documentation and transparent communication during the transition process are emphasized to minimize disruptions and maintain community trust. This may involve identifying alternative maintainers, documenting essential processes, and providing guidance for users migrating to new solutions.

• Data and vendor lock-in considerations

Consideration of data and vendor lock-in is paramount for the sustained viability of open source projects. Strategies to minimize dependencies that may lead to lock-in are crucial. This includes evaluating data portability and adopting standards that facilitate seamless transitions. 

By adopting open standards and fostering a modular architecture, projects can enhance their ability to adapt and thrive independently of particular vendors or proprietary technologies.

Final thoughts

Embarking on the open source journey requires a combination of technical acumen, community engagement, and a commitment to best practices. While it may seem daunting, the innovation, collaboration, and access to a global community of like-minded individuals open source software brings are well worth the effort. 

Open source is not just a development model, it’s a dynamic ecosystem that thrives on diversity, transparency, and the collective pursuit of building something meaningful.