Open Source Basics — Lesson 1
What Open Source Means
Learning Objectives
- 1Define open source and distinguish it from free software.
- 2Understand how open source licenses affect business use.
- 3Recognize the role of open source in modern technology.
Open source beyond free
Open source software makes its source code publicly available for anyone to inspect, modify, and distribute. The term "open source" is often confused with "free," but they are different concepts. Open source refers to access to the code, not the price. Many open source projects are free to use, but others charge for hosting, support, or enterprise features.
Most of the software infrastructure that powers the modern internet is open source: Linux runs the majority of servers, WordPress powers over 40% of websites, PostgreSQL and MySQL handle enormous amounts of business data, and frameworks like React, Next.js, and Django power applications used by millions.
For business leaders, understanding open source matters because your organization almost certainly depends on it — whether you know it or not. Your website, your CRM, your cloud infrastructure, and your AI tools are built on open source foundations.
Licenses and what they mean for business
Open source licenses define how the code can be used, modified, and distributed. Permissive licenses like MIT and Apache 2.0 allow almost any use, including commercial use, with minimal restrictions. Copyleft licenses like GPL require that modifications also be open sourced.
For business use, the license determines whether you can use the software in your commercial product, whether you must share your modifications, and what attribution is required. Most business-friendly open source uses permissive licenses that impose few obligations.
When evaluating open source for business use, check the license first. If your legal team has concerns about GPL-licensed code in a commercial product, look for alternatives with permissive licenses. For internal tools, the license type matters less because you are not distributing the software.
Open source in your technology stack
Audit your technology stack and you will likely find open source everywhere: the server operating system, the database, the web framework, the programming language, the content management system, the monitoring tools, and dozens of libraries and packages that your developers use.
This pervasiveness is generally positive — open source provides high-quality software at lower cost, with the ability to inspect and modify the code. The risks include: depending on projects with insufficient maintenance, using software with vulnerabilities that are not patched quickly, and integrating components with incompatible licenses.
Understanding that your business runs on open source changes how you evaluate vendors, plan maintenance, and think about technology risk. It also opens up conversations about whether contributing to open source communities benefits your organization.
Case Study
The library that broke the internet
Situation
In 2016, a developer removed a small open source package called "left-pad" (11 lines of code) from the npm registry. Thousands of applications and websites that depended on it broke simultaneously, including major services. The incident revealed how deeply interconnected open source dependencies are.
Analysis
The left-pad incident demonstrated that open source dependencies form complex chains. A tiny package deep in the dependency tree can affect thousands of projects. Business applications built on modern frameworks typically have hundreds of direct and indirect open source dependencies.
Takeaway
Your application depends on more open source code than you realize. Understanding and managing these dependencies is a business responsibility, not just a technical one.
Reflection Questions
- 1. Do you know how much open source software your organization technology stack depends on?
- 2. Has your organization ever experienced a problem caused by an open source dependency?
Key Takeaways
- ✓Open source means code access, not necessarily free — licenses define what you can do.
- ✓Most modern technology infrastructure is built on open source foundations.
- ✓Permissive licenses (MIT, Apache) are business-friendly; copyleft licenses (GPL) have restrictions.
- ✓Your organization almost certainly depends on open source — understanding it is a business necessity.