Metacommunity theory is an extension of metapopulation theory with the goal of understanding how ecological communities vary through space and time. One off-shoot of metacommunity theory deals with understanding how community structure varies along biotic or environmental gradients. The Elements of Metacommunity Structure framework is a three-tiered analysis of metacommunity structure that enables the user to identify metacommunity properties that arise in site-by-species incidence matrices. These properties can then be related to underlying variables that influence species distributions. The EMS framework is now implemented in metacom, an open source R package that allows for the analysis and plotting of metacommunities.