Screwdriver is a self-contained, pluggable service to help you build, test, and continuously deliver software using the latest containerization technologies. Screwdriver began as a hack for simplified interfacing with Jenkins at Yahoo in 2012. As the volume of builds increased, it became clear that Jenkins was not stable or feasible to use at the scale we were running builds. In 2016, we rebuilt Screwdriver from scratch in open source with our best coding practices and CICD goals in mind. Screwdriver is executor and SCM-agnostic, meaning you can choose whichever plugin better suits your need or build your own. It's completely free and open source, and our team is actively maintaining the code.