This chapter demonstrates how the study of composing technologies has improved and expanded understanding of writing activity writ large. It argues that human bodies matter—the ways bodies interact with and use tools and the ways race, gender, sexual identity, able bodiness, and class mark the bodies in culture. The chapter describes two ways composing technologies have revealed writing's materiality. The ways are: attention to the design of effective learning spaces and the kinds of infrastructural support those learning spaces require, and attention to how the specific technologies within the physical spaces shaped what writers actually do. The initial recognition that writing is an embodied practice led to further descriptive and empirically grounded attention to the embodied, lived experience of writers occupying a number of social identity categories. Writing studies' approach to composing technologies thus is not only about the mechanics of writing but about the technologies through which people write and the essence of writing.