Warewulf is an operating system management toolkit designed to facilitate large scale deployments of homogeneous and heterogeneous systems on physical, virtual and cloud based infrastructures. Originally, the Warewulf project pioneered the concept of stateless computing in HPC, setting the standard for large-scale cluster provisioning. It provided two functions, provisioning and monitoring but the two functions did not communicate within Warewulf itself, nor was it possible to hook other functions directly into Warewulf itself. Today, Warewulf is more than just a basic provisioning and monitoring solution as it now implements an abstract, object-oriented data store and a modular interface that facilitates a highly extensible, customizable feature set. Current and planned modules include monitoring (operating system, services, filesystems, etc.), provisioning, power management, user management, configuration management, event/trigger handling and notification, scheduler integration, cloud services (both local and remote), etc.