Choose a license without guessing.
This guide explains the most common open source licenses you will meet around NuGet packages, then helps you narrow the field based on reciprocity, patent language, and commercial reuse.
9
4 families
Apache 2.0
License Wizard
Step 1 of 5
Common Licenses At A Glance
Use the atlas below when you already know the license family you want, but still need the practical tradeoffs spelled out.
| License | Reciprocity | Patent Grant | Closed Source | Typical Fit |
|---|---|---|---|---|
| MIT License | No reciprocity | No | Allowed | Minimal friction for libraries, tooling, SDKs, and commercial adoption. |
| Apache License 2.0 | No reciprocity | Yes | Allowed | A strong default when enterprise adoption and patent clarity matter. |
| BSD 2-Clause License | No reciprocity | No | Allowed | A clean permissive option when you want a short text and traditional BSD wording. |
| BSD 3-Clause License | No reciprocity | No | Allowed | Good when you want permissive reuse with extra protection against implied endorsement. |
| Mozilla Public License 2.0 | File-level reciprocity | Yes | Allowed | A pragmatic middle ground between permissive licenses and strong copyleft. |
| GNU LGPL 3.0 | Library-level reciprocity | Yes | Allowed | Useful when you want stronger protection than MPL but still allow proprietary consumers in some architectures. |
| GNU GPL 3.0 | Strong copyleft | Yes | Restricted | Choose this when preserving software freedom is more important than frictionless proprietary adoption. |
| GNU AGPL 3.0 | Network copyleft | Yes | Restricted | The right tool when you want hosted-service operators to share modifications too. |
| The Unlicense | No reciprocity | No | Allowed | Use when you want to waive as much control as practical and keep legal ceremony near zero. |
MIT License
The shortest mainstream open source license: broad permission, one notice obligation, almost no friction.
- NuGet libraries that want the lowest possible adoption barrier.
- Internal platform tooling that may later be open sourced.
Apache License 2.0
A permissive license like MIT, but with a clearer patent grant and more structured notice rules.
- Widely distributed NuGet packages used inside commercial products.
- Developer platforms where patent certainty matters.
BSD 2-Clause License
A compact permissive license close to MIT, with attribution but without the 3-clause endorsement rule.
- Infrastructure, utilities, and package components where low-friction adoption matters.
- Teams already aligned with BSD-style legal language.
BSD 3-Clause License
A permissive BSD variant that adds a non-endorsement clause on top of the standard attribution rules.
- Packages distributed by organizations that care about brand separation.
- Teams that want MIT-like freedom with explicit non-endorsement wording.
Mozilla Public License 2.0
A file-level copyleft license: modified MPL-covered files stay open, but larger combined works can remain proprietary.
- Libraries where you want collaboration on core files without blocking commercial adoption.
- Framework components that may be embedded in larger proprietary systems.
GNU LGPL 3.0
A library-focused copyleft license that allows proprietary use under conditions, especially around relinking and replacement rights.
- Reusable libraries where you want improvements to the library itself to stay open.
- Cases where downstream proprietary apps may link rather than copy library internals.
GNU GPL 3.0
A strong copyleft license that requires distributed derivative works to remain GPL-compatible and share source.
- Projects that want strong leverage to keep downstream derivatives open.
- Community-first tools where commercial closed redistribution is undesirable.
GNU AGPL 3.0
A GPL-style copyleft license that also reaches network-delivered software, not just distributed binaries.
- Server software and SaaS platforms where network use is the main delivery model.
- Projects that want the strongest reciprocal pressure available in mainstream OSS licensing.
The Unlicense
A public-domain-style dedication with a permissive fallback, optimized for maximum reuse and minimum barriers.
- Samples, snippets, tiny utilities, and throwaway tooling.
- Projects where extreme reuse freedom matters more than legal precision.