This chapter proposes a global view of the set of dynamics of interplay that were generated in the early modern publishing sector around a single astronomical work, the Tractatus de sphaera by Johannes de Sacrobosco. The Sphaera, a thirteenth-century tract of geocentric cosmology, rather than remaining a static text, became over the centuries a multiauthored dynamic textual tradition. This essay argues that publishers, printers, and booksellers had a fair share of agency not only in perpetuating but also in shaping the evolution of this long-lasting textual tradition. The present essay traces the ways this agency was configured.