Base package for 'outsider' < https://github.com/ropensci/outsider>. The 'outsider' package and its sister packages enable the installation and running of external, command-line software within R. This base package is a key dependency of the user-facing 'outsider' package as it provides the utilities for interfacing between 'Docker' < https://www.docker.com> and R. It is intended that end-users of 'outsider' do not directly work with this base package.