Open Source License Compliance

Open source license compliance means meeting the legal obligations required by the licenses attached to open source software you use. These obligations often include preserving copyright notices, including license text, and providing attribution or source code when required. Compliance ensures you can legally use, modify, and distribute open source software without risk. Failing to comply can lead to legal, financial, and operational consequences.

Open source compliance is important because open source licenses are legally enforceable agreements. Violations can result in lawsuits, forced source code disclosure, or delays in product releases and acquisitions. Compliance also demonstrates operational maturity and reduces risk during audits, customer reviews, and due diligence events. Many compliance issues occur simply because obligations were not tracked.

Permissive licenses such as MIT, BSD, and Apache 2.0 allow broad use, modification, and distribution with minimal obligations. Copyleft licenses impose stricter requirements, often requiring derivative works to be released under the same license. Strong copyleft licenses like GPL and AGPL apply to the full derivative work, while weak copyleft licenses like LGPL apply only to the licensed component. Understanding this difference is critical for commercial software teams.

Strong copyleft licenses require that any derivative work be distributed under the same license terms. Examples include GPL v2, GPL v3, and AGPL v3. These licenses typically require source code disclosure when software is distributed or, in the case of AGPL, when software is accessed over a network. Strong copyleft licenses carry higher compliance risk for proprietary products.

The Affero General Public License extends copyleft obligations to software accessed over a network. If you modify AGPL licensed software and users interact with it remotely, you may be required to provide access to the full corresponding source code. This makes AGPL particularly risky for SaaS and cloud based applications. Many organizations restrict or prohibit AGPL usage as a result.

GPL requires that derivative works be released under the same license when distributed. LGPL is a weaker copyleft license designed primarily for libraries and allows proprietary software to link to the library without open sourcing the entire application. However, modifications to the LGPL licensed library itself must still be released under the LGPL. This distinction makes LGPL more acceptable in commercial products.

Common obligations include preserving copyright notices, including license text, providing attribution, and delivering required License or Notice files. Some licenses also require publishing component disclosures or providing source code upon request. Obligations vary significantly by license type and usage context. Tracking these requirements consistently is essential for compliance.

An open source compliance checklist should include an inventory of all open source and commercial components in use. It should verify approved licenses, ensure copyright and license text are preserved, and confirm required disclosures are published. Many checklists also include vulnerability scanning and processes for responding to source code requests. A documented checklist helps teams scale compliance across products.

Yes, open source software can be used in commercial products if you comply with the license terms. Permissive licenses generally allow commercial use with minimal requirements. Copyleft licenses may impose source code disclosure or licensing obligations that affect proprietary software. Reviewing license terms before use is critical for commercial teams.

If no license is present, there is no legal permission to use, modify, or distribute the code. The absence of a license means the code is fully copyrighted by the author. Using unlicensed code creates significant legal risk and should be avoided unless explicit permission is obtained. License identification is a core part of compliance.