RADICAL is a multi-purpose 2-D radiative transfer code for axi-symmetric circumstellar (or circum-black-hole) envelopes /disks / tori etc. It has been extensively tested and found reliable and accurate. The code has recently been supplemented with a Variable Eddington Tensor module which enables it to solve dust continuum radiative transfer problems from very low up to extremely high optical depths with only a few (about 7) iterations at most.

DISKSTRUCT is a simple 1+1-D code for modeling protoplanetary disks. It is not based on multidimensional radiative transfer! Instead, a flaring-angle recipe is used to compute the irradiation of the disk, while the disk vertical structure at each cylindrical radius is computed in a 1-D fashion; the models computed with this code are therefore approximate. Moreover, this model cannot deal with the dust inner rim.

In spite of these simplifications and drawbacks, the code can still be very useful for disk studies, for the following reasons:

• It allows the disk structure to be studied in a 1-D vertical fashion (one radial cylinder at a time). For understanding the structure of disks, and also for using it as a basis of other models, this can be a great advantage.
• For very optically thick disks this code is likely to be much faster than the RADMC full disk model.
• Viscous internal heating of the disk is implemented and converges quickly, whereas the RADMC code is still having difficulty to deal with high optical depth combined with viscously generated internal heat.

RADMC is a 2-D Monte-Carlo code for dust continuum radiative transfer circumstellar disks and envelopes. It is based on the method of Bjorkman & Wood (ApJ 2001, 554, 615), but with several modifications to produce smoother results with fewer photon packages.

RADMC-3D is a software package for astrophysical radiative transfer calculations in arbitrary 1-D, 2-D or 3-D geometries. It is mainly written for continuum radiative transfer in dusty media, but also includes modules for gas line transfer and gas continuum transfer. RADMC-3D is a new incarnation of the older software package RADMC (ascl:1108.016).