Changes in version 2.7.4                        

    o   the observed Fisher information matrix is now returned 
	as attribute ('FisherI') of the returned object

                        Changes in version 2.7.3                        

    o   New baseline hazard family: inverse Weibull (Fréchet)

                         Changes in version 2.7                         

    o   optimization is now based on the optimx package

    o   the default optimizer is now nlminb (from the stats package)

    o   fixed issue in the likelihood with lognormal frailties

    o   new function coeff()

                        Changes in version 2.6.0                        

    o   new baseline distribution: log-skew normal

                 Changes in version 2.5.10 (2015-09-03)                 

    o   added Kendall's tau for the lognormal frailty distrubution

                         Changes in version 2.5                         

    o   new frailty distrubution available: lognormal

                        Changes in version 2.01                         

    o   Added function anova.parfm() to compare models

                        Changes in version 1.01                         

    o   Added stratification

                       Changes in version 0.66-2                        

    o   Added example datasets