This document discusses using Oscar, which is a set of Vagrant plugins and templates, to develop and test Puppet code locally using a virtualized environment. Oscar builds a full Puppet Enterprise environment on top of Vagrant and allows configuring virtual machines, setting up a master node and agent nodes, and testing Puppet code using tools like RSpec. The document provides details on Oscar commands, file configuration, customizing Oscar for specific needs, and links to documentation and examples for further reference.