A 10 Simple Rules paper on collaborative lesson development. All material can be re-used under the Creative Commons - Attribution license.
Lessons take significant effort to build, and even more effort to maintain. The collaborative code development methods pioneered by the open source community offer a way forward, allowing us to create lessons which are open, accessible, and continually updated and improved by a community of contributors. This paper provides ten simple rules that can help others create sustainable lessons.
Graphical Abstract.