What is "Copyleft"?
At the heart of the GPL family is "copyleft," a licensing mechanism that ensures software and its derivatives remain free and open. When you use copyleft code, you're obligated to share your own modifications under the same terms. We'll explore the three main types below.
GPL (General Public)
Strong Copyleft
Known for its "viral" nature. If you use GPL code, your entire derivative product must also be licensed as GPL. It's designed to keep software completely open.
LGPL (Lesser General)
Weak Copyleft
More business-friendly. It allows proprietary software to link to an LGPL library without the entire application becoming open source. Ideal for creating reusable components.
AGPL (Affero General)
Network Copyleft
The most restrictive, it closes the "server loophole." If software is used over a network, any modifications must be shared with all users, ensuring services remain open.
The Core Dilemma: Balancing Open Source with IP Protection
For a biotech startup, intellectual property is paramount. The choice of an open source license directly impacts your ability to protect and commercialize your core innovations. This chart illustrates the IP risk associated with different license types for a company with a proprietary business model.
A Tale of Three Licenses
Each GPL license offers a different balance of freedom and restriction. This comparison highlights their key features, helping you decide which path aligns with your company's strategic goals for a specific software component.
GPL is for tools, not treasure. While powerful for research tools like GROMACS that accelerate science, its viral nature makes it highly risky for your core, patentable product.
LGPL is for libraries. It's the ideal choice when you want to build a foundational library that others (including commercial entities) can use, fostering a collaborative ecosystem without compromising their proprietary code.
AGPL is for open services. Choose this only if your goal is to ensure that any service built on your code, even if just hosted online, remains fully open source. It's a powerful statement but can deter commercial adoption.
The Open Source Business Model Spectrum
How do you build a sustainable business on free software? Open source companies typically adopt one of three primary models to generate revenue while staying true to the collaborative spirit.
Dual Licensing
Offer the software under a free, open-srouce license (e.g. GPL) and a separate commercial license. The commercial license allows proprietary use without the copyleft restrictions.
Open Core
The core functionality is free and open source. Offer premium, proprietary features, add-ons, or plugins for a fee. This is a very common and successful model.
Services & Support
The software is entirely free. Revenue comes from selling expert support, training, custom development, and consulting services (e.g. Red Hat's model).
The Attribution Imperative: Staying Compliant
Attribution isn't optional—it's a legal cornerstone of every open source license. Proper attribution builds trust, respects creators, and protects your company from legal risk. Below are the key elements of a robust attribution strategy.
License Files
Always include the full, unmodified text of the original license in your project (`LICENSE` or `COPYING` file).
Copyright Notices
Preserve all original copyright notices within the source code files. Never remove them.
Documentation
Provide clear attribution in your project's documentation (e.g., in a README or an "About" section), acknowledging the open source components you use.
A Founder's Decision Framework
Navigating the GPL maze requires a strategic approach. Follow this framework to make informed decisions that align with your business goals and protect your valuable intellectual property.
1. Assess Commercial Goals
Is this part of your proprietary core or a foundational tool?
2. Audit All Code
Inventory all open source components and their licenses from day one.
3. Define IP Boundaries
Clearly separate your proprietary code from open source components.
4. Implement a Policy
Create clear guidelines for your team on acceptable license usage.
5. Seek Legal Counsel
This is not optional. Engage patent attorneys early to avoid costly mistakes.