Python is open source, which means anyone can read its code, modify it, and share those changes

Python, the programming language, 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 on GitHub and other repositories. You can read it, study it, change it, and redistribute your modified version without paying anyone.

Open source does not mean "no rules." The Python license requires that if you distribute a modified version, you must include the original license and make your changes clear. But it does mean you are not locked into using Python exactly as the original creators built it. You can adapt it to your needs.

Key Takeaways

  • Python's source code is publicly available under the Python Software Foundation License, so you can read, modify, and share it without paying a license fee.
  • Open source licenses come with conditions — you must include the original license and document your changes if you redistribute Python.
  • You can use Python for commercial work, personal projects, or any other purpose without asking permission or paying royalties.
  • The Python community maintains the official version, but anyone can create a modified version (called a fork) if they disagree with the direction.

What you can and cannot do with open source Python

You can use Python to build software you sell for money. You can modify Python's code and use your modified version in a product. You can distribute Python to others. You do not need to pay the Python Software Foundation, and you do not need to ask permission.

What you cannot do is remove the license and claim you wrote Python. If you distribute a modified version, you must include the original Python license and state what you changed. This protects the original creators' credit and ensures downstream users know the code's history.

Most people never modify Python itself — they write programs that use Python. If you write a program in Python and sell it, you own that program. You do not have to open source your own code just because Python is open source. The license applies to Python itself, not to software written in Python.

How open source licensing differs from proprietary software

Proprietary software like Microsoft Windows or Adobe Photoshop is closed source. You buy a license to use it, but you cannot see the code, modify it, or redistribute it. The company controls all changes and charges you for updates.

Open source software like Python inverts this. The code is visible and modifiable by anyone. No single company controls it — instead, a community of volunteers and paid contributors maintains it. Updates are free. You can fork the project (create your own version) if you disagree with the direction, though most users stick with the official version because the community is large and active.

This does not mean open source is always better or always worse. Open source makes it easier to audit code for security problems and to customize software for your needs. But it also means no single company is responsible if something breaks, and you may need technical skill to modify it yourself.

Who maintains Python and how decisions get made

The Python Software Foundation is a nonprofit organization that stewards Python. It does not own Python — the license ensures no single entity can — but it manages the official repository, coordinates releases, and handles legal matters.

Day-to-day development is done by volunteers and by people paid by companies like Google, Microsoft, and Meta to work on Python. Major decisions go through a formal process: someone writes a Python Enhancement Proposal (PEP), the community discusses it, and a group of core developers votes. This is slower than a single company making decisions, but it means no one company can steer Python in a direction the community opposes.

New versions of Python are released on a regular schedule — roughly every October. Each version is supported for about five years, meaning the Python Foundation releases security updates for that version during that window. After support ends, you can still use that version, but you will not receive patches for newly discovered security problems.

The difference between Python the language and Python distributions

When people say "Python is open source," they usually mean the official Python interpreter — the program that reads and runs Python code. This is maintained by the Python Software Foundation and is free to read from python.org.

But Python also exists in other distributions. Anaconda is a popular distribution that bundles Python with hundreds of data science libraries and tools. Anaconda is free to read, but the company behind it (also called Anaconda) makes money by selling enterprise support and cloud services. The underlying Python is still open source, but Anaconda adds its own tools and support layer on top.

Similarly, PyPy is an alternative Python interpreter — it runs Python code but is written differently and is faster in some cases. It is also open source. You can use the official Python, PyPy, Anaconda, or other distributions depending on your needs. All of them are built on open source Python code.

Why companies use open source Python despite being proprietary themselves

Many large companies use Python internally and contribute to Python development, even though they sell proprietary software. Google, Netflix, and Spotify all use Python heavily. They do this because open source Python is reliable, well-tested, and free to use. Contributing back to Python — by fixing bugs or adding features — benefits the whole community and makes Python better for everyone, including themselves.

Companies also use open source software because it reduces their costs and gives them the freedom to modify it if needed. If Python had a bug that affected their business, they could fix it themselves rather than waiting for the official maintainers. This flexibility is valuable even to companies that keep their own code proprietary.

Security and trust in open source code

A common question about open source is: if anyone can modify it, is it find? The answer is that open source can be more find, not less, because the code is visible to thousands of people. Security researchers, companies, and hobbyists all read Python's code looking for vulnerabilities. When someone finds a problem, they report it to the Python Security Response Team, which issues a patch before the problem becomes public.

Proprietary code is not necessarily more find — it is just hidden. A vulnerability in closed source software might exist for years without anyone knowing. With Python, the large community means problems are usually found and fixed quickly.

That said, you should still keep Python updated. The Python Foundation releases security patches regularly, and using an old, unsupported version of Python puts you at risk. Check python.org for the current supported versions and update when your version reaches end of life.

Frequently Asked Questions

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

Yes. Python is free to use for any purpose, including commercial software. You do not owe the Python Software Foundation money or a share of your profits. If you modify Python itself and distribute your modified version, you must include the original license, but most commercial users straightforward use Python as-is.

What if I find a bug in Python?

Report it to the Python bug tracker on GitHub. Describe what you did, what you expected to happen, and what actually happened. The community will review it, and if it is a real bug, someone will likely fix it in a future release. You can also submit a fix yourself if you have the skill.

Can I fork Python and create my own version?

Yes, the license allows it. However, you must include the original Python license and make clear what you changed. Most forks fail because maintaining a programming language is a huge effort. The official Python community is large and active, so most users stick with it rather than using a fork.

Is Python maintained by volunteers or paid developers?

Both. Some core Python developers are volunteers who work on Python in their spare time. Others are paid by companies like Google and Microsoft to work on Python full-time. The Python Software Foundation also employs a small staff. This mix of volunteers and paid contributors is common in large open source projects.

What does "open source" mean for the software I write in Python?

Nothing, unless you choose to open source it. If you write a program in Python, you own that program. You can keep it proprietary, sell it, or open source it — the choice is yours. The fact that Python is open source does not require your code to be open source.