Open Source License Scanners

TL;DR:

Open-source software is everywhere, but it comes with legal problems and compliance risks. Open Source License Scanners help you track and manage software licenses to avoid open source license violations, lawsuits, and compliance headaches. If you don’t know what licenses your dependencies use, you’re rolling the dice on legal trouble.

• Protects: Software projects, intellectual property, legal compliance
• Type: Application Security Posture Management (ASPM)
• Fits in SDLC: Build and Deploy phases
• AKA: License Compliance Scanning, OSS License Auditing
• Support: Open-source dependencies, third-party components, package managers (npm, PyPI, Maven)

What is an Open Source License Scanner?

An Open Source License Scanner analyzes software dependencies to identify the licenses they use. Many open-source projects come with open source license rules, and using them incorrectly can lead to legal problems and financial risks. These tools help organizations:

• Identify license obligations – Know what legal terms apply to each dependency.
• Detect conflicts – Find non-standard licenses or compatibility issues that could break compliance.
• Avoid lawsuits – Prevent unauthorized use of restrictive open-source code.
• Simplify compliance – Automate legal checks in CI/CD pipelines.
• Track license information – Maintain an up-to-date record of all third-party components used.

Pros and Cons of Open Source License Scanners

Pros:

• Prevents legal risks – Helps avoid open source license violations and compliance breaches.
• Automates compliance – Reduces manual review effort in managing dependencies.
• Tracks license changes – Keeps up with evolving open source license rules.
• Simplifies audits – Generates reports for legal teams and compliance officers.

Cons:

• False positives – Some tools over-report or misinterpret license information.
• Doesn’t cover proprietary risks – Only focuses on open-source licenses.
• Limited enforcement – Can detect violations but not automatically fix them.

What Does an Open Source License Scanner Do Exactly?

These tools scan software codebases and third-party components to:

• Detect open-source licenses – Identifies GPL, MIT, Apache, BSD, and other licenses.
• Check for compliance violations – Alerts on non-standard licenses, missing attributions, and legal risks.
• Generate Software Bill of Materials (SBOMs) – Provides an inventory of all dependencies.
• Monitor for license changes – Tracks updates that could introduce compliance risks.
• Analyze license images – Extracts licensing details from metadata and files.

What Does an Open Source License Scanner Protect You From?

• Open source license violations – Avoids unauthorized use of restrictive open-source code.
• Legal disputes – Prevents lawsuits over non-compliant software usage.
• Compliance failures – Ensures alignment with industry and legal requirements.
• Hidden dependencies – Uncovers third-party components with risky licenses.

How Does an Open Source License Scanner Work?

These scanners operate by:

1. Parsing code and dependencies – Reads package manifests, source files, and SBOMs.
2. Extracting license data – Identifies license images and license information declared in dependencies.
3. Comparing against policies – Checks licenses against open source license rules and company policies.
4. Alerting on risks – Flags incompatible or high-risk licenses.
5. Generating compliance reports – Provides documentation for audits and legal teams.

Popular tools like ScanCode Toolkit, a Linux Foundation Project, help automate this process at scale.

Why and When Do You Need an Open Source License Scanner?

You need a License Scanner when:

• You use open-source dependencies – Any software using open-source code is subject to open source license rules.
• You distribute software – Avoid shipping non-compliant code that could lead to legal problems.
• You work in regulated industries – Compliance is essential for enterprise, government, and healthcare software.
• You manage multiple teams/projects – Ensures company-wide license compliance across development teams.

Where Does an Open Source License Scanner Fit in the SDLC Pipeline?

These tools are most effective in the Build and Deploy phases:

• Build Phase: Scans dependencies before release to catch compliance issues early.
• Deploy Phase: Ensures deployed software follows licensing requirements.

How Do You Choose the Right Open Source License Scanner?

A good scanner should:

• Support multiple package managers – Works with npm, PyPI, Maven, Go, and more.
• Provide detailed reporting – Generates compliance documentation for audits.
• Integrate with CI/CD – Automates scanning in development pipelines.
• Detect nested dependencies – Analyzes indirect dependencies for code dependency tracking.

If you’re using open source, you need to track your licenses—or risk paying the price.

Best Open Source License Scanners 2025

(To be filled in later)

Open Source License Scanner FAQs

1. What happens if I violate an open-source license?

It depends on the license. Some, like the MIT or Apache licenses, have minimal restrictions. Others, like the GPL, require you to open-source your modifications. If you ignore these rules, you could face legal problems, reputational damage, or even forced code disclosure.

2. Do I need a license scanner if I only use “permissive” open-source licenses?

Yes. Even permissive licenses like MIT and Apache have attribution requirements. Also, third-party components could include restrictive non-standard licenses, meaning you might unknowingly introduce compliance risks.

3. Can open-source license scanners detect proprietary code issues?

No. These tools only analyze open-source licenses. If you’re worried about proprietary code leaks or legal problems, you’ll need additional code scanning tools for code dependency tracking.

4. How do license scanners handle multi-license projects?

Some software projects mix multiple licenses, which can create compliance issues. A good license scanner will:

• Identify all license information used in a project.
• Flag conflicting open source license rules (e.g., MIT mixed with GPL).
• Provide guidance on legal problems and implications.

5. What is ScanCode Toolkit and how does it help?

ScanCode Toolkit, a Linux Foundation Project, is an open-source tool that scans software repositories to detect license information, analyze dependencies, and check for open source license violations. It’s widely used for code dependency tracking and compliance automation.