Glossary

Open source license

What Is an Open Source License?

An Open Source License is a legal agreement that defines how open-source software may be used, modified, and distributed. It protects both developers and users by clearly outlining rights and responsibilities.

Open source does not mean software without rules. It means that the source code is publicly accessible, subject to specific licensing terms.

Types of Open Source Licenses

License TypeExamplesKey Rule
PermissiveMIT, Apache 2.0, BSDFew restrictions
CopyleftGPL, AGPL, LGPLDerivatives must remain open-source
Weak CopyleftMPLOnly modified files must remain open-source

Copyleft licenses are sometimes referred to as “share-alike” because modifications must also remain open-source when distributed.

Why Open Source Licenses Matter

Open-source software powers modern technology, from cloud platforms and developer tools to AI frameworks and operating systems. Misunderstanding a license can:

  • Require disclosure of proprietary code
  • Create compliance or legal violations
  • Restrict commercial use
  • Trigger legal disputes

Teams must understand the legal impact before using open-source software.

Common Terms in Open Source Licenses

Most Open Source Licenses define:

  • Attribution requirements
  • Redistribution rules
  • Warranty disclaimers
  • Patent clauses
  • Commercial use allowances
  • Modification rights

Some licenses even extend obligations into hosted SaaS environments.

Open Source License Best Practices

Organizations should:

  • Track all software dependencies
  • Review license impact early
  • Avoid mixing incompatible licenses
  • Educate developers
  • Automate license scanning

This prevents problems later in the development lifecycle.

Frequently asked questions

Are all Open Source Licenses the same?

No. Some are permissive while others enforce share-alike rules.

Can open-source software be used commercially?

Often yes, but conditions may apply.

Do Open Source Licenses expire?

Typically no. Terms apply indefinitely.

Is attribution always required?

Most licenses require credit to the original authors.

Do Open Source Licenses include warranties?

Almost always no. They generally disclaim liability.