The generator of this poster is the tree sort algorithm, the subject are all the trees, algorithmic exercises and human beings involved in the residency of Anaïs Berck at the Villa Empain and ESA Saint-Luc Bruxelles in October 2021. The images and texts are sorted following different criteria: time, colour and the natural element in the alt-text description of the images. Tree sort or binary search tree allows for fast lookup, addition, and removal of data items, and can be used to implement dynamic sets and lookup tables. The basic operations include: search, traversal, insert and delete.They are used in relational databases, data compression code, in Unix kernels for managing a set of virtual memory areas, and more. The binary search tree algorithm was discovered independently by several researchers, including P.F. Windley, Andrew Donald Booth (UK), Andrew Colin (UK), Thomas N. Hibbard (US), and attributed to Conway Berners-Lee (UK) and David Wheeler (UK), in 1960 for storing labelled data in magnetic tapes.