This workshop is a practical guide to using the most efficient software in phylogeny at present, PHYML. PHYML is primarily a tool for obtaining a phylogenetic tree from an alignment of protein or nucleic sequences, but it also provides a wide choice of evolutionary models and evaluation procedures. In this workshop the emphasis will be strictly on obtaining a useful tree from an alignment. We will not cover model or tree testing. Minimum theory will be covered. Moreover, the alignment step will be considered solved. If time permits, we will try to cover use of PHYML on the web, on your PC, and on the Vital-IT cluster.