Open Source Licensing: What Every Startup CTO Must Know
GPL, MIT, Apache, BSL — understanding open-source licenses before they become legal liabilities.
Open source powers modern software development. But every open-source dependency in your stack comes with a license — and those licenses have legal implications that can range from minor to existential.
License Categories
Permissive Licenses (MIT, BSD, Apache 2.0)
- Allow commercial use with minimal restrictions
- Generally startup-friendly
- Must include original copyright notice
- Apache 2.0 includes patent grant (important for IP-heavy companies)
Copyleft Licenses (GPL, LGPL, AGPL)
- Require derivative works to be released under the same license
- GPL: If you link GPL code, your entire application may need to be GPL
- LGPL: Dynamic linking exception — more flexible for library usage
- AGPL: Extends GPL to network use — critical for SaaS companies
Source-Available (BSL, SSPL, Elastic License)
- Not truly open source (by OSI definition)
- May restrict commercial use or competition
- Increasingly common among VC-backed open-source companies
Critical Risks for Startups
The AGPL Trap
If your SaaS product includes ANY AGPL-licensed code, you may be required to release your entire source code. This can be existential for a proprietary SaaS startup.
License Incompatibility
Mixing GPL and Apache code in the same binary? Could create an impossible legal obligation. Track your dependency tree's licenses carefully.
Due Diligence Red Flags
Investors and acquirers will audit your open-source usage. Common deal-killers:
- Undocumented GPL dependencies in proprietary code
- No open-source policy for engineering teams
- Missing license compliance documentation
Best Practices
1. Maintain a Software Bill of Materials (SBOM) for all dependencies
2. Implement automated license scanning in your CI/CD pipeline
3. Create an open-source policy that defines acceptable licenses
4. Choose your own license carefully if releasing open source
5. Document everything — compliance documentation is your defense
Dual Licensing Strategy
If you're building an open-source product with a commercial model:
- Community edition under a permissive or copyleft license
- Enterprise edition under a commercial license
- Requires contributor license agreements (CLAs)
The Lexium Approach
We help CTOs and engineering leaders navigate open-source licensing with precision. From SBOM audits to license compliance frameworks, we ensure your open-source strategy supports your business model rather than undermining it.