When you share your code on GitHub, one of the most important choices you need to make is which license to use. The license you choose will decide how others can use, change, and share your code. In this article, I’ll give you a simple overview of some of the most common open source licenses and what they mean for your project.

1. What Is an Open Source License?

An open source license is a legal document that gives others permission to use, change, and share your code under certain conditions. Without a license, the default is that no one else can legally use your code. Choosing the right license makes sure that others can benefit from your work while following the rules you set.

2. Common Open Source Licenses

Here’s a quick look at some of the most popular open source licenses:

1. MIT License

• Overview: The MIT License is one of the most permissive licenses available. It allows others to do almost anything with your code, as long as they include the original license and copyright notice in any copies or significant parts of the software.
• When to Use: Use this license if you want your code to be as accessible as possible and don’t mind if it’s used in proprietary (closed-source) projects.
• Example: “This project is licensed under the MIT License.”

2. Apache License 2.0

• Overview: The Apache License 2.0 is similar to the MIT License but includes extra protections for contributors. It requires anyone who distributes your code to include a copy of the license and any notices or attributions.
• When to Use: Use this license if you want a permissive license with more specific terms about patents and attribution.
• Example: “This project is licensed under the Apache License 2.0.”

3. GPL (General Public License)

• Overview: The GPL is a strong copyleft license, which means that any new work you create must also be open source and use the GPL license. This is to ensure that the code and any changes stay free and open.
• When to Use: Use this license if you want to make sure that all derivative works are also open source and share the same freedoms as your original code.
• Example: “This project is licensed under the GNU General Public License v3.0.”

4. BSD License

• Overview: There are two common versions of the BSD License: the 2-clause and the 3-clause. Both are permissive like the MIT License, but the 3-clause version includes a “no endorsement” clause, preventing the use of the name of the project or its contributors to promote derived products.
• When to Use: Use this license if you like the permissiveness of the MIT License but want to include a “no endorsement” clause.
• Example: “This project is licensed under the BSD 3-Clause License.”

5. Creative Commons Licenses

• Overview: Creative Commons licenses are often used for content like documentation, images, and other non-software assets. They offer a range of options, from very permissive (CC BY) to more restrictive (CC BY-NC-ND, which doesn’t allow commercial use or derivatives).
• When to Use: Use these licenses if your project includes non-code content that you want to license separately.
• Example: “The content of this project is licensed under the Creative Commons Attribution 4.0 International License.”

3. How to Choose the Right License

Choosing the right license depends on what you want for your project. Here are some questions to consider:

• Do you want to allow commercial use of your code? Permissive licenses like MIT or Apache are good choices.
• Do you want to make sure that any changes to your code stay open source? Consider using a copyleft license like the GPL.
• Is your project a mix of code and content? You might need to combine a software license (like MIT) with a Creative Commons license for content.

4. How to Add a License to Your Project

Adding a license to your project on GitHub is easy:
1. Choose a License: Decide which license fits your project best.
2. Add a License File: Create a LICENSE file in the root of your repository and paste the text of your chosen license.
3. Mention the License: In your README.md, mention the license you’ve chosen, like this:

License
This project is licensed under the MIT License - see the LICENSE file for details.

5. Conclusion

Choosing the right license for your open source project is an important step in sharing your work with the world. It not only protects you legally but also makes clear how others can use your code. Whether you choose a permissive license like MIT or a copyleft license like GPL, make sure you understand the implications and pick the one that fits your goals.

If you’re still unsure which license to choose, GitHub offers a Choose a License tool that can help you decide. Or you can read this article with a full overview of licenses here.

Thanks for reading! If you have any questions or want to share your experiences with open source licenses, feel free to leave a comment!