1. One or more non-transitory computer-readable media having instructions stored thereon that when executed by one or more computers cause the one or more computers to: identify one or more items of configuration information collected from a plurality of virtualized computing systems running on a same physical machine, each virtualized computing system of the plurality of virtualized computing systems comprising an operating system instance distinct from operating system instances of other virtualized computing systems of the plurality of virtualized computing systems; display a user interface comprising a data tree that summarizes, at a first level of granularity, the one or more items of configuration information collected from the plurality of virtualized computing systems and comprises one or more differentiating node icons that visually identify one or more groups of virtualized computing systems, of the plurality of virtualized computing systems, identified based on their domain membership and association with a portion of the one or more items of configuration information collected from the plurality of virtualized computing systems that comprises configuration information differing from saved reference data for the one or more groups of virtualized computing systems; and responsive to a user selection of a differentiating node icon, of the one or more differentiating node icons, corresponding to a group of the one or more groups of virtualized computing systems, display, on the user interface, at a second level of granularity, and for the group of the one or more groups of virtualized computing systems, a portion of the configuration information differing from the saved reference data for the one or more groups of virtualized computing systems, wherein the second level of granularity is more detailed than the first level of granularity.