One of the reasons for Ruby‘s popularity as a programming language is Ruby gems, the collection of open-source libraries that can be downloaded and used by developers around the world. With tens of thousands of gems available, there’s no doubt that they make Ruby a more productive, interesting, and collaborative language. The fact that anyone can contribute a gem makes it even more appealing and democratic. But not all gems incorporate practices that encourage their widespread use, as well as contributions from other developers. In this talk, Mat Brown provides seven ground rules for gem designers that, when followed, will make your gem more appealing to developers — those who want to use your gem, and those who want to help make it even better.