MULTIFORTE started as a direct FORTRAN 77 translation of the MULTI program written in BASIC by K. Yamaoka et.al [Yamaoka, 1981].
MULTI was written for a microcomputer in BASIC and allowed for the nonlinear least squares analysis of integrated equations. The four fitting algorithms were included in this original program. Later versions of MULTI incorporated Bayesian fitting and numerical integration of differential equations as separate programs [Yamaoka, 1983; Yamaoka, 1985].
MULTIFORTE includes normal fitting, Bayesian estimation, or simulation only with integrated or differential equation models in the one program. Also, the selection of weighting schemes and methods for numerical integration has been expanded. With MULTIFORTE the pharmacokinetic model is written in FORTRAN 77, compiled and linked with the rest of the program.
BOOMER was developed with the same fitting and numerical integration routines found in MULTIFORTE. However, with BOOMER the model is described using model parameters (based on the approach used by SAAM v23).