Yes, Python is open source and free to use

Python is released under the Python Software Foundation License, which is an open source license. This means the source code — the human-readable instructions that make Python work — is publicly available for anyone to read, modify, and redistribute. You can download Python at no cost from python.org, use it for any purpose (commercial or personal), and modify it if you have the technical skill to do so.

Open source does not mean unmaintained or unsupported. Python is actively developed by a core team of volunteers and funded by the Python Software Foundation, a nonprofit organization. New versions are released regularly with security updates, performance improvements, and new features. Thousands of companies — including Google, Netflix, Spotify, and NASA — rely on Python for production systems.

Key Takeaways

  • Python's source code is publicly available under an open source license, and you can download and use it for free without paying licensing fees.
  • You can modify Python's code and redistribute your changes, but you must include the original license and give credit to the Python Software Foundation.
  • Open source does not mean you get paid support — the Python community offers free help through forums and documentation, but commercial support is available separately.
  • Many popular tools and libraries built on Python (like Django, NumPy, and Flask) are also open source, so your entire development stack can be free.

What open source means in practice

When software is open source, the developers who created it have made the underlying code visible and modifiable by the public. For Python, this means you can inspect exactly how the language works, report bugs you find, and even submit fixes. The Python source code is hosted on GitHub, where anyone can see the changes made in each version and understand why decisions were made.

Open source licenses come with specific rules about what you can and cannot do. Python's license allows you to use, copy, modify, and distribute Python — including for commercial purposes — as long as you include a copy of the license and do not claim you wrote the original code. If you modify Python and release your version publicly, you must make your changes available under the same license.

In practice, most people download Python as-is and do not modify the core language. They write their own programs in Python, which can be open source, closed source, or anything in between. Your code does not have to be open source just because you wrote it in Python.

How Python's open source model differs from closed source languages

Closed source languages like C# (owned by Microsoft) and Swift (owned by Apple) are proprietary. You cannot see or modify their core code, and you typically pay a license fee to use them, though some offer free tiers for development. The companies that own them control what features are added and when security updates are released.

Python's open source model means no single company controls the language. Decisions about Python's future are made by the Python Enhancement Proposal (PEP) process, where anyone can propose changes and the community votes. This has made Python more responsive to user needs and less dependent on any one vendor's business decisions. If you disagree with a direction Python is taking, you can fork the code (create your own version) — though in practice, the community consensus is strong enough that forks are rare.

The trade-off is that open source projects rely on volunteer labor. Python's core team is small relative to the size of the user base. If you need may provide response times or dedicated support, you can purchase commercial support from companies like JetBrains, ActiveState, or Anaconda, but that is optional.

The ecosystem of open source tools built on Python

One major advantage of Python being open source is that the most popular libraries and frameworks built on top of it are also open source. Django (a web framework), NumPy (numerical computing), Pandas (data analysis), and Flask (a lightweight web framework) are all free and open source. This means your entire development stack — from the language itself to the tools you use daily — can be built on code you can inspect and modify.

This ecosystem is maintained by a mix of volunteers, companies that use the tools, and some funded maintainers. Many of these projects accept donations or have corporate sponsors. The open source nature means if a tool stops being maintained, the community can fork it and continue development, so you are not locked into depending on a single vendor's roadmap.

Security and transparency in open source Python

Because Python's code is public, security researchers can inspect it for vulnerabilities. This is sometimes called "many eyes make all bugs shallow" — the more people who can read the code, the more likely bugs are caught. When a security issue is found in Python, the core team is notified privately and given time to fix it before the vulnerability is publicly disclosed.

The downside of open source is that once a vulnerability is public, attackers can see it too. However, Python's release cycle is fast enough that patches are usually available within days. You can check the Python security page to see all known vulnerabilities and which versions are affected.

For production systems, you should keep Python updated to the latest patch version in your chosen release series. Python 3.12 is the current stable version, and older versions (3.11, 3.10, 3.9) receive security updates for several years after release.

Licensing restrictions you should know about

Python's license is permissive, meaning it places few restrictions on what you can do. You can use Python in commercial products, proprietary software, and closed source projects without paying anything. The main requirement is that if you distribute Python itself (not just code written in Python), you must include the license text.

If you modify Python's core code and distribute your modified version, you must release those modifications under the same license. This is called copyleft — it ensures that improvements to Python stay available to everyone. However, if you write a program in Python and distribute it, your program can be closed source even if Python itself is open source.

Some organizations have concerns about open source licenses for legal or compliance reasons. If your company has a legal team that reviews dependencies, they should review Python's license (it is short and straightforward). In practice, Python's license is considered very permissive and rarely causes issues in enterprise environments.

How to contribute to Python if you want to

Because Python is open source, you can contribute improvements back to the project. This can be as simple as reporting a bug on the Python issue tracker, writing documentation, or submitting code fixes. The Python community has a Code of Conduct and a formal process for proposing changes through PEPs.

Most contributors are volunteers who use Python professionally and want to improve it. Some are employed by companies that use Python heavily and allocate time for contributions. You do not need permission to start — you can fork Python on GitHub, make changes, and submit a pull request. The core team will review it and either merge it, ask for changes, or decline it with feedback.

If you are not ready to contribute code, you can help by testing new versions, answering questions in forums, or improving documentation. The Python community values all forms of contribution.

Frequently Asked Questions

Can I use Python in a commercial product without paying anything?

Yes. Python's license allows commercial use at no cost. You do not owe the Python Software Foundation money or attribution in your product — you only need to include Python's license if you distribute Python itself alongside your product. Most companies bundle Python with their applications and simply include the license file.

What if I modify Python and want to keep my changes private?

You can modify Python for internal use without releasing your changes. The license only requires you to share modifications if you distribute your modified version publicly. If you modify Python and use it only within your organization, you do not have to share those changes.

Is Python really maintained if it is open source?

Yes. Python is maintained by the Python Software Foundation and a core team of developers. New versions are released every year, and security updates are provided for several years per release. Python is one of the most actively maintained programming languages in the world.

Can a company take Python, modify it, and sell it as their own?

Legally, no. Python's license requires that anyone distributing Python (modified or not) include the original license and credit the Python Software Foundation. Selling Python without attribution would violate the license. In practice, companies do create Python distributions with their own tools and support (like Anaconda or ActiveState), but they clearly identify Python as the underlying open source project.

What happens if the Python Software Foundation shuts down?

The code would remain available under the open source license. Anyone could fork it and continue development. This is one of the key protections of open source — the project cannot be taken proprietary or abandoned in a way that locks users out, because the code is already public.