This article introduces the notion of evolutionary textual environment as the outcome of a digital experiment. The experiment consisted of transforming a digital archive of Fernando Pessoa's Book of Disquiet into a changing textual space sustained by role-playing interactions. As conceptual and technical artifact, this living archive expresses an innovative model not only for the literary acts of reading, editing and writing, but also for reimagining the book as a network of reconfigurable and dynamic texts, structures, and actions. The programmed features of the LdoD Archive can be used in multiple activities, including leisure reading, study, analysis, advanced research, and creative writing. Through the integration of computational tools in a simulation space, this collaborative archive provides an open exploration of the procedurality of the digital medium itself. The "unfinished machine" metaphor suggests the open-endedness both of the evolving textual environment and of the computational modeling of literary performativity that sustains the whole experiment.