Here is a list of all modules with brief descriptions:

Ncompositional_terms	This module contains all that is required to perform compositional modelling. NOTE THAT THIS FUNCTIONALITY HAS NEVER BEEN FULLY IMPLEMENTED ONLY INERT COMPOSITIONAL WORKS CURRENTLY
Ncopy_outof_state	This module enables the multiphase prototype code to interact with state by copying everything required from state to ICFERST, adaptive time-stepping, outfluxes computation, tunneled BCs and Darcy velocity
Ncv_advection	This module contains all the tools to assemble and solve the equations and fields associated with the CV mesh, i.e. transport equation, continuity equation, DCVFE gradient matrix and the Laplacian system for the zeta-potential
Niphreeqc	IPHREEQC module from the PHREEQC project, needed to interact with PHREEQCRM
Nmatrix_operations	This module contain subroutines to deal with the ICFERST matrices format. This includes MATVECS and MATMAT operations All of this should be replaced by PETSc
Nmulti_data_types	This module contains all the ICFERST structures and associated subroutines (allocate/deallocate) Use it also to identify what a variable means since here they are described
Nmulti_interpolation	This module contains the conservative mesh to mesh interpollation for DG fields, as described in Adam et al. 2016 doi: http://dx.doi.org/10.1016/j.jcp.2016.05.058
Nmulti_machine_learning	Module to load and call a XGBoost model
Nmulti_phreeqc	All the subroutines required to handle the connection with PHREEQCRM
Nmulti_pipes	This module contains all the subroutines to assemble and solve for pipes
Nmulti_sp	This module contains all the necessary subroutines to deal with self Potential in ICFERST
Nmulti_surface_tension	This module contains the subroutines to include surface tension. Currently only used for INERTIA
Nmulti_tools	This module contains the generic subroutines required by ICFERST, for example quicksort
Nmultiphase_1d_engine	This module contain all the necessary subroutines to deal with FE-wise equations and fields. Assembling and solving of the momentum equation and associated fields such as capillary pressure, hydrostatic pressure solver, and stabilisation techniques. Also includes the assembly and solving of a Laplacian system (for zeta potential mainly)
Nmultiphase_eos	This module contains subroutines related to the equations of state and other properties such as relative permeabilities, capillary, flash, etc
Nmultiphase_time_loop	Time-loop module of IC-FERST. This module contains the time-loop and the non-linear loop. The time-loop consists many steps: 1) Data initialisation including shape functions, memory allocation, sparsity, porous media properties, etc. 2) Initialisation of the actual time loop. 3) Non-linear loop. IC-FERST uses a modified Anderson-acceleration non-linear solver, which is based in a Picard iterative non-linear solver. In this way, the different equations are solved independently and coupled through the Anderson non-linear solver. First the momentum and continuity equations are assembled and solved for, next the different transport equations are solved, for example: saturation, temperature, concentration, etc. ActiveTracers and Species are solved within the non-linear solver while PassiveTracers are solved outside the non-linear solver. 4) Once the non-linear solver has converged, we proceed to jump to the next time-level but first we check if we need to adapt the mesh and/or generate a vtu file. etc
Nphreeqcrm	Fortran Documentation for the geochemical reaction module PhreeqcRM
Nsetbasicfortrancallbackf
Nshape_functions_linear_quadratic	Shape function subroutines for multi-dimensions for Quadrilaterals, Triangles, Hexaedra and Tetrahedra
Nshape_functions_ndim	This module contains subroutines to generate the shape functions for multi dimensions
Nshape_functions_prototype	SHAPE FUNCTIONS SUBRTS
Nsolvers_module	All the subroutines associated to solving non-linear systems, Schur complement, etc
Nspact	Sparsity for the Matrices?
Nsparsity_1d	Subroutines associated with the CSR storage used for 1D
Nsparsity_nd	Subroutines associated with the CSR storage used in ICFERST
Nxgb_interface	Interface to call XGBoost library C API from fortran