Rough Guide to Open-Source Licenses

This page is a rough reminder of the key provisions of the most common open source licenses. This is not legal advice, use at your own risk. Licenses are roughly arranged in order of permissiveness, most permissive first.

Common Clauses


Public Domain

Simplified (2-clause) BSD License [1999]

New (3-clause) BSD License [1990]

Old (4-clause) BSD License [1990]

Apache License 2.0 [2004]

Mozilla Public License

For changes to the code itself:

Lesser GNU Public License v2 [1991]

For distributed changes to the code itself:

GNU Public License v2 [1991]

For any distributed derivative work including the code:

GNU Public License v3 [2007]

For any distributed derivative work including the code:

Affero GNU Public License v3 [2007]

For any derivative work including the code:


Copyright (c) 2011 David Drysdale

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