Pythia 8: Simulating Tau-Lepton Decays

As of version 8.150 of Pythia, the isotropic decays of τ-leptons have been replaced with a decay machinery that incorporates full spin correlations and more sophisticated decay models. Developments of the Pythia τ-lepton decay machinery from version 8.150 up to version 8.201 are summarized. The τ-lepton decay machinery in Pythia 8 is described, including the spin correlation algorithm, the available τ-lepton decay models, and the user interface.