  Probabilistic programming frameworks are powerful tools for statistical
modelling and inference. They are not immediately generalisable to phylogenetic
problems due to the particular computational properties of the phylogenetic
tree object. TreeFlow is a software library for probabilistic programming and
automatic differentiation with phylogenetic trees. It implements inference
algorithms for phylogenetic tree times and model parameters given a tree
topology. We demonstrate how TreeFlow can be used to quickly implement and
assess new models. We also show that it provides reasonable performance for
gradient-based inference algorithms compared to specialized computational
libraries for phylogenetics.
