The MCML program was created in 1994 by Lihong Wang and Steven Jacques while they worked together at the University of Texas M. D. Anderson Cancer Center, in the Laser Biology Research Laboratory. The program allows multiple planar layers of tissue, each with different optical properties (μa, μs, g, n) and thickness.
The work was based on the previous work by Marleen Keijzer, Scott Prahl and Steven Jacques, but added the feature of multiple tissue layers.
A companion program called CONV provides convolution of MCML output files against flat-field or Gaussian-shaped spatial beam profiles
Alternative website for downloads: Lihong Wang's Lab
Other Monte Carlo programs: omlc.org/software/mc