DensiTree 2.7.6 for Mac can be downloaded from our website for free. DensiTree for Mac is categorized as Education Tools. The actual developer of this free software for Mac is Remco Bouckaert.
From the developer:
DensiTree is a program for qualitative analysis of sets of trees. Bayesian hierarchical clustering methods provide a powerful tool for phylogenetic analysis, linguistic research, and hierarchical clustering in general, such as applied in marketing, political science, customer preference grouping, etc. Bayesian methods use MCMC sampling, which results in a large number of trees representing the distribution over all possible hierarchies.
You may want to check out more Mac applications, such as iRNAi, Xfoil or DesignWorks Professional, which might be similar to DensiTree.