Fortran must die
As in this example.
Another consideration is the method of estimation used by these programs to produce the parameter estimates, either maximum likelihood (ML) or restricted maximum likelihood (REML). Each has its own advantages and disadvantages. ML is better for unbalanced data, but it produces biased results. REML is unbiased, but it cannot be used when comparing two nested models with a likelihood ratio test. Both methods will produce the same estimates for fixed effects, yet they do differ on the random effect estimates (Albright & Marinova, 2010).