A tiny contributor license agreement for public-private licensing projects.
Download the most recent release from GitHub, or read the current development version of the terms in Markdown format.
Licenses are prescription-strength legal devices. If you need terms, don't be an doofus. Hire a lawyer. A good one will ask good questions. They may decide this form fits your needs.
Do not put confidential information about you, your work, or your clients in issues or pull requests. Do not ask for legal advice on GitHub, or try to disguise requests for legal advice as general questions or hypotheticals. You don't want advice from anybody dumb enough to fall for that.