Introduction
What is open source? Today, open source software (OSS) underpins modern tech, from web servers to AI systems.
Understanding open source fundamentals is crucial for developers, businesses, and technology enthusiasts alike. These concepts build upon fundamentals of software development and complement fundamental software concepts.
According to the Open Source Initiative’s definition of Open Source…
Open source software is software that is freely redistributable, provides access to its source code, allows modifications and derivative works, ensures non-discriminatory use, and is governed by a license that preserves these freedoms without imposing restrictions on other software or specific technologies.
Open source history began with pioneers like Richard Stallman and the Free Software Foundation (FSF), who promoted software freedom. In 1998, Bruce Perens and Eric S. Raymond founded the Open Source Initiative (OSI) to promote and protect open source software, and to develop licenses and standards.
The divide between the Free Software Foundation and the Open Source Initiative is their philosophies. The FSF focuses on ethical software freedom, while the OSI emphasizes the practical benefits of collaboration, innovation, and transparency.
Type: Explanation (understanding-oriented).
Primary audience: beginner to intermediate - developers and tech professionals learning open source principles and practices.
This article explains what open source is, why it matters, and everyday activities around open source projects. It doesn’t teach how to contribute step by step, but it provides a mental model to understand guides and docs.
If you’re new to open source, start with the principles and benefits sections. Licensing, governance, and business models provide a broader context.
Section 1: The Open Source Definition (OSD)
The Open Source Definition (OSD) lists the criteria a license must satisfy to be considered “open source” under the Open Source Initiative (OSI).
- Free Redistribution: The software can be freely shared and distributed without restrictions.
- Source Code Availability: The source code must be accessible to users, allowing them to study, modify, and improve the software.
- Derived Works: Users can create and share modified software, known as derivative works.
- Integrity of the Author’s Source Code: The original author’s rights and attribution must be preserved in derivative works.
- No Discrimination Against Persons or Groups: The license cannot discriminate against anyone.
- No Discrimination Against Fields of Endeavor: The license does not restrict anyone from using the program in a specific field of endeavor.
- Distribution of License: The rights attached to the program must apply to all to whom the program is redistributed without the need to execute an additional license by those parties.
- License Must Not Be Product-Specific: The rights attached to a program must not depend on its inclusion in a particular software distribution.
- License Must Not Restrict Other Software: The license must not restrict other software bundled with it.
- License Must Be Technology-Neutral: No license depends on specific technology or interface style.
Key takeaway: People often talk about “open source” as if it were a vibe or a culture. The OSD anchors it in something enforceable, the license.
Section 2: Benefits of Open Source
For Individuals
As an individual, engaging with open source can offer several benefits, including:
- Learning and Development: Opportunities for education, collaboration, and skill development.
- Portfolio Building: Building a portfolio and gaining visibility in the tech community.
- Career Opportunities: Potential career opportunities and professional growth through open source contributions.
- Community Impact: The satisfaction of giving back to the community and making a positive impact.
- Access to Software: Access to free and high-quality software.
For Organizations
For organizations, adopting open source can provide numerous advantages, such as:
- Cost-Effectiveness and Flexibility: Lower licensing costs, more flexibility, and often a stronger security review posture.
- Innovation and Development: Faster iteration by building on existing work and collaborating with external contributors.
- Reputation and Talent: Stronger employer brand, easier hiring, and more trust through transparency.
- Interoperability and Compliance: Less vendor lock-in and better alignment with common standards.
- Sustainability and Responsibility: Healthier long-term roadmaps when the ecosystem can outlive any single vendor.
Section 3: Open Source Licensing
Open source licensing is often a personal choice, but understanding license implications is crucial.
Most license obligations activate only when distributing software, not during internal use. This explains the confusion around open source licensing.
Let’s compare these OSI-approved licenses. The license text is the source of truth, with edge cases emerging quickly in projects.
“License Compatibility” refers to how well a license can be combined with other software licenses.
MIT
Permissive.
- Allows proprietary use: Yes.
- Requires source code disclosure: No.
- Patent terms: No explicit patent license grant.
- Compatibility notes: Often compatible in practice, but check your dependency and distribution model.
GNU General Public License (GPL)
Strong copyleft.
- Allows proprietary use: No, if you distribute derivative works, you must comply with the GPL.
- Requires source code disclosure: Yes, for distributed derivative works.
- Patent terms: Version-dependent, GPLv3 includes explicit patent provisions, GPLv2 differs.
- Compatibility notes: Limited, and context-dependent.
Apache
Permissive.
- Allows proprietary use: Yes.
- Requires source code disclosure: No.
- Patent terms: Includes an explicit patent license grant.
- Compatibility notes: Often compatible, but compatibility depends on how you combine and distribute code.
BSD
Permissive.
- Allows proprietary use: Yes.
- Requires source code disclosure: No.
- Patent terms: No explicit patent license grant.
- Compatibility notes: Often compatible in practice, but check your dependency and distribution model.
Mozilla Public License (MPL)
Weak copyleft.
- Allows proprietary use: Yes, with conditions.
- Requires source code disclosure: Yes, for modified files you distribute.
- Patent terms: Includes explicit patent provisions, scoped to contributions.
- Compatibility notes: Moderate, and context-dependent.
Many open source projects and organizations choose OSI-approved licenses like MIT, GPL, or Apache because they’re widely understood, legally vetted, and benefit from long-standing ecosystem norms.
Understanding open source licenses is vital for creators and users to ensure compliance and avoid legal issues. Projects need to prevent license violations and respect creator rights. If not redistributing, you can use the software freely, but check the license.
An organization should have a clear open source licensing policy to ensure compliance, manage risks, and protect intellectual property. This includes guidelines for using, contributing to, and releasing open source software, along with regular audits to monitor license compliance. License misuse can lead to serious issues.
Key takeaway: Licenses set rules for creators and users; understanding them clarifies boundaries.
Section 4: Contributing to Open Source
Contributing to open source is rewarding, enabling collaboration, skill-building, and community impact.
Most open source contributions follow a typical lifecycle, which are conceptual phases, not a checklist.
- Engagement: You observe the project, ask questions, and build context about what the maintainers care about.
- Project selection: You find a project that aligns with your interests, constraints, and risk tolerance.
- Change work: You make a code change, documentation improvement, or issue triage contribution.
- Validation: You test or otherwise validate that your change does what you claim it does.
- Review and iteration: You submit the change, receive feedback, and iterate until it is accepted or consciously declined.
The diagram shows the typical contribution flow from first contact to repeated contributions.
(context and trust)" as Engagement state "Project fit
(scope and risk)" as Fit state "Change work
(code or docs)" as Change state "Validation
proof it works" as Validate state "Review and iteration
feedback loop" as Review state "Merge
and learn" as Merge [*] --> Engagement Engagement --> Fit Fit --> Change Change --> Validate Validate --> Review Review --> Merge Merge --> Engagement: Repeat classDef phase fill:#F4F1FF,stroke:#5B4B8A,stroke-width:2px,color:#1A1A1A; classDef review fill:#E8F6FF,stroke:#1D6FA5,stroke-width:2px,color:#1A1A1A; classDef merge fill:#E9FBEF,stroke:#1D7A3F,stroke-width:2px,color:#1A1A1A; class Engagement,Fit,Change,Validate phase; class Review review; class Merge merge;
Key takeaway: Contribution is a relationship. The code matters, but the communication and follow-through usually matter more.
Contributions usually move from discovery, to a change, to review, to merge, then repeat over time.
Notable Open Source Projects
Here are some major open source projects that have significantly impacted the tech industry:
- Linux: Computer operating systems.
- Git: Software version control.
- Kubernetes: Software container orchestration.
- TensorFlow: Artificial Intelligence and Machine Learning (AI/ML).
Section 5: Managing Open Source Projects
Managing open source projects involves various tasks.
Open source project health tends to revolve around a handful of recurring dimensions. These are conceptual lenses, not a sequence.
- Direction and documentation: Clear goals, contribution guidelines, and documentation that reduce contributor friction.
- Community operations: Issue triage, PR review, communication norms, and inclusive culture.
- Engineering quality: Automation, reviews, testing, and release discipline.
- Licensing and compliance: Clear licensing intent, contributor sign-off norms, and policy alignment.
- Sustainability: Funding, maintainer bandwidth, governance, and long-term stewardship.
The diagram below highlights the typical “system” that forms around an open source project as it scales.
Key takeaway: Open source projects are socio-technical systems that require shipping code, but trust and predictability sustain them. As projects grow, they develop repeatable systems for planning, collaboration, quality, compliance, and sustainability.
Section 6: Open Source Community and Culture
A few recurring ingredients shape open source culture, appearing in nearly every healthy project.
- Collaboration and communication: Public discussion, shared context, and visible decision-making.
- Inclusivity and diversity: Lowering barriers so more people can contribute meaningfully.
- Governance and decision-making: Clear rules for decision-making and dispute resolution.
- Recognition: Social reinforcement, credit, and appreciation that keep people engaged.
- Events and conferences: Places where relationships form and shared identity grows.
The diagram maps how community ingredients connect, from tooling to events and recognition.
and
Communication" as CollaborationAndCommunication state "Tools
and Platforms" as ToolsAndPlatforms state "Inclusivity
and
Diversity" as InclusivityAndDiversity state "Educational
Resources" as EducationalResources state "Governance
and
Decision-Making" as GovernanceAndDecisionMaking state "Codes of
Conduct" as CodesOfConduct state "Mentorship
Programs" as MentorshipPrograms state "Recognition
and
Rewards" as RecognitionAndRewards state "Documentation
and
Guidelines" as DocumentationAndGuidelines state "Events
and
Conferences" as EventsAndConferences [*] --> CollaborationAndCommunication CollaborationAndCommunication --> ToolsAndPlatforms ToolsAndPlatforms --> InclusivityAndDiversity InclusivityAndDiversity --> EducationalResources EducationalResources --> GovernanceAndDecisionMaking GovernanceAndDecisionMaking --> CodesOfConduct CodesOfConduct --> MentorshipPrograms MentorshipPrograms --> RecognitionAndRewards RecognitionAndRewards --> DocumentationAndGuidelines DocumentationAndGuidelines --> EventsAndConferences EventsAndConferences --> CollaborationAndCommunication: Repeat classDef phase fill:#F4F1FF,stroke:#5B4B8A,stroke-width:2px,color:#1A1A1A; classDef loop fill:#E9FBEF,stroke:#1D7A3F,stroke-width:2px,color:#1A1A1A; class CollaborationAndCommunication,ToolsAndPlatforms,InclusivityAndDiversity,EducationalResources,GovernanceAndDecisionMaking,CodesOfConduct,MentorshipPrograms,RecognitionAndRewards,DocumentationAndGuidelines,EventsAndConferences phase; class Sustainability loop;
Key takeaway: Communities require more than goodwill; projects succeed when expectations are clear, and contributors feel safe, respected, and effective.
Tooling fosters collaboration, shaping culture reinforced by governance, recognition, and events.
Section 7: Open Source in Business
Companies value open source for innovation, collaboration, and growth. Contributing to projects and community engagement provide benefits such as faster iteration, lower costs, and access to talent.
open source business models like open core, dual licensing, and SaaS allow projects to be monetized while maintaining openness. Many successful projects focus on infrastructure components such as databases, as explained in the fundamentals of databases.
A business earns revenue through open source by offering support, consulting, training, and customization, with companies like Red Hat, MongoDB, and Docker each providing unique value.
Key takeaway: Open source offers leverage, but capturing value needs a business model. “Free as in source code” doesn’t mean “free as in sustainable.”
How Google Leverages Open Source
Google heavily leverages open source, contributing to projects like Kubernetes, TensorFlow, and Chromium, and actively engages with the community.
What Other Companies Are Leading in Open Source?
Other companies leading in open source include:
- Microsoft: Microsoft has embraced open source, contributing to VS Code, TypeScript, and .NET Core.
- IBM: IBM has a long history of supporting open source and contributing to Apache, Linux, and Hyperledger.
- Meta’s open source projects, such as React, GraphQL, and PyTorch, foster innovation and collaboration among developers.
- Amazon: Amazon has contributed to open source projects like Apache MXNet, AWS SDKs, and Firecracker, helping developers build scalable, secure cloud apps.
- Netflix: Netflix open sourced projects like Spinnaker, Falcor, and Conductor, sharing expertise in cloud-native architectures and DevOps.
Many companies like Apple, Uber, Airbnb, and others actively contribute to and engage with open source communities.
Section 8: Open Source Business Models
While Section 7 explains why businesses use open source, this section details their main mechanisms for capturing value.
Open source business models are diverse and evolving, reflecting changes in technology, innovation, and entrepreneurship. Here are five common open source business models:
Open Core: Companies provide a core open source product with proprietary features or services for enterprise customers, allowing them to monetize open source projects by offering enhanced functionality, support, or services not in the open source version.
Dual Licensing: Companies offer open source software under a copyleft license and commercial licenses for proprietary use, enabling them to serve both the open source community and commercial users needing proprietary licensing.
Software as a Service (SaaS): Companies provide cloud-based open source services, earning through subscriptions or usage fees. This model uses cloud scalability and accessibility to deliver open source software as a service and generate recurring revenue.
Consulting and Support: Companies offer consulting, training, and support for open source software users and customers. This model delivers expertise and assistance to help organizations implement, customize, and maintain their open source solutions.
Community and Ecosystem: Companies develop open source communities around their products, encouraging collaboration and innovation. This model highlights community engagement and contributions, creating a vibrant ecosystem that supports and drives the success of their open source projects.
Adopting these models helps companies monetize open source projects while upholding openness and transparency.
Section 9: The Future of Open Source
The future of open source evolves, shaping tech, education, and policy. It heavily influences AI, blockchain, and cloud computing, allowing global developer collaboration. Open source communities and tools reduce barriers to software creation and sharing. Impacts differ: some ecosystems, like Linux and Kubernetes, benefit mainly from shared infrastructure, while others gain from open standards and transparent procurement.
Open source revolutionizes learning by providing free, high-quality resources for students and educators. It transforms education models, promotes collaboration, creativity, and lifelong learning. Embracing open source helps institutions boost engagement, foster digital literacy, and prepare for future work.
Open source promotes transparency, accountability, and citizen engagement, helping governments deliver services efficiently. It supports open government, civic participation, and data-driven decisions. Adopting open source can enhance services, cut costs, and build trust, fostering innovation, collaboration, and social impact.
The future of open source links technology, education, and governance. It creates opportunities for individuals, organizations, and societies. Embracing it unlocks technological potential, empowers learners and educators, and helps us build inclusive, transparent, and sustainable communities.
Key takeaway: Open source expands, but the complex problems are social and economic. Governance, funding, and incentives decide what survives.
Post Open
Bruce Perens, founder of the Open Source Initiative, believes open source has failed. He claims the movement hasn’t met its goals of promoting software freedom and empowering users. Perens suggests future software development should focus on new models that prioritize user autonomy, privacy, and security, challenging proprietary software and centralized platforms.
He believes open source has become a corporate welfare program benefiting big tech at the expense of developers and users. He argues the ecosystem is unsustainable and calls for reevaluating its values and goals to meet digital age challenges.
“We have a great corporate welfare program. Our users are the richest companies in the world. Indeed, we’ve enabled companies like Google to be created. In contrast, if our developers aren’t working for those companies, they probably go uncompensated.” Bruce Perens, at FOSDEM 2024.
Conclusion
💡 Open source is more than a software development model; it is a philosophy, culture, and movement that empowers people, organizations, and societies to collaborate, innovate, and create positive change.
Many open source projects power distributed systems and cloud infrastructure, concepts covered in fundamentals of distributed systems.
By embracing open source, we join the global community’s collective intelligence, creativity, and passion for building a better, more inclusive, and sustainable future for all.
Whether you’re an individual, a business, or a government, open source offers opportunities to engage, contribute, and make an impact. Participating in projects, sharing knowledge, and supporting communities help shape the future of technology, education, and governance, fostering positive change.
This article is explanation-focused. Use it to orient yourself, then consult guides when ready to act.
Call to Action
If you want to move from understanding to action, these resources are good next steps for finding projects and contribution workflows.
Here are some resources to help you get started:
- Finding Projects: GitHub Explore, A List of Open Source Projects.
- Learning Platforms: freeCodeCamp, Open Source Guides.
- Communities: Reddit r/opensource, TODO Group, InnerSource Commons.
Related Articles
Related fundamentals articles:
Software Engineering: Fundamentals of Software Development shows how open source contributions help you practice software development skills. Fundamental Software Concepts provides the core concepts that underpin all software, including open source projects. Fundamentals of Software Testing teaches you how to test open source contributions effectively.
Infrastructure: Fundamentals of Databases shows how many open source projects power database systems. Fundamentals of Distributed Systems helps you understand how open source projects enable distributed systems.
Communication: Fundamentals of Technical Writing is essential for maintaining open source projects and helping contributors understand codebases.
References
- Open Source Initiative’s definition of Open Source.
- Open Source Licenses.
- MIT License text.
- BSD 2-Clause License text.
- Apache License, Version 2.0 text.
- GNU General Public License, Version 2 text.
- GNU General Public License, Version 3 text.
- Mozilla Public License, Version 2.0 text.
- Open Source Business Models.
- Open Source at Google.
- Exploring the future of Open Source.
- What Comes After Open Source?.
- Is Open Source ever Hyphenated?.
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