A software package for fitting and comparing failure-time models within the R software environment ( This tool empowers users to perform the model fitting, ranking, and testing procedures described in Skalski and Whitlock (2020). Included in this software are: (1) routines for fitting non-parametric Kaplan-Meier survival estimates from the generalized F distribution and Vitality families of parametric failure time models; (2) specialized plotting tools; (3) methods for ranking alternative models using a goodness-of-fit metric; (4) and more. Main dependencies include the R packages: flexsurv, survival, and vitality.

Source code for this software is publicly accessible on GitHub. The package carries Version 3 GNU General Public License (GPLv3), which guarantees openness of derivative works and forbids proprietization.

Current Version