CC BY (Creative Commons Attribution) is the most accommodating of public copyright licenses as defined by Creative Commons, a nonprofit organization that provides legal tools for sharing and use of creative works and research. The CC BY license is recommended for maximum dissemination and use of licensed materials. All PLOS content is available under CC BY, meaning anyone is free to use and reuse the content provided the original source and authors are credited. CC BY is the appropriate license for publicly funded research; it maximizes the potential for both economic and scholarly impact, protects the rights of authors and strengthens the long-standing tradition of appropriate attribution and credit for scholarship.