Here are the classes, structs, unions and interfaces with brief descriptions:

[detail level 12]

►NFieldNames
CCFRecord
►NPythonInterface
CPythonBasalFriction	BasalFriction that calls a python function to compute $\beta^2$
CPythonIBC	PythonInterface::PythonIBC, a PhysIBC-derived class which allows the bedrock and topography to be set by a user-defined python function f(x,y)
CPythonIceTemperatureIBC	PhysIBC-derived class that allows the internalEnergy to set a a user-defined python function f(x,y,sigma,thickness,topography,surface)
CPythonMuCoefficient
CPythonSurfaceFlux	Use a python function to evaluate the surface flux
CPythonVelocitySolver
CAMRDamage	Continuum damage model
►CAmrIce	Class to manage non-subcycled AMR ice-sheet model
CObserver	Part of Observer-Observee implementation
CAmrIceBase	Abstract base class for amr ice sheet models (AmrIce, AMRIceControl)
CAMRMelange	Continuum melange transport model
CArrheniusRateFactor	Arrhenius Rate Factor
CAVCAMRPoissonOp
CAVCAMRPoissonOpFactory
CAxbyFlux	Provide the flux ax + by, where x,y are fluxes and a,b are scalars
CAxbyMuCoefficient
CBasalFriction
CBasalFrictionPowerLaw	Implements BasalFrictionRelation to provide a power law
CBasalFrictionRelation	Virtual base class for basal friction relations
CBasicThicknessIBC	Physical/domain initial and boundary conditions
CBennCalvingModel
CBoxBoundedFlux	Applies a flux inside a box and (optionally inside a time interval) and zero outside
CCalvingModel	Virtual base for calving models
CcfDiagnostic
CCGSolver
CCircularSupportConstantRealFunction
CCliffCollapseCalvingModel	A calving model which implements the Pollard and DeConto cliff-collapse mechanism using the ice mask
CCompactSupportConstantRealFunction
CCompactSupportInclinedPlaneFunction
CCompositeCalvingModel	Calving model which lets us compose multiple calving models
CCompositeFlux	Adds together a list of fluxes
CconstantFlux	Simple implementation of SurfaceFlux which sets surface flux to a constant in space and time
CconstantFriction	BasalFriction where $\beta^2$ is constant in space and time
CConstantIceTemperatureIBC	Concrete IceInternalEnergyIBC that sets ice temperature to be constant
CConstantRateFactor	Constant Rate Factor
CConstantRealFunction
CConstitutiveRelation	Abstract class around the englacial constitutive relations for ice
CCopyBasalFriction	Allows pre-defined basal friction coefficients to be passed in and copied
CCrevasseCalvingModel
CDamageCalvingModel
CDamageConstitutiveRelation	Computes the effective viscosity $\mu$ including a factor due to crevassing
CDamageIceObserver	Contains an AMRDamage, responds to changes in the ice sheet state
CDamagePhysIBC	PhysIBC for the damage model
CDeglaciationCalvingModelA
CDeglaciationCalvingModelB
CDomainDiagnosticData
CDomainEdgeCalvingModel	Ensure open ocean on one or more domain edges
CExtrudedPieceWiseLinearFlowline
CFASIceSolver
CFASIceViscouseTensorOp
CFASIceViscouseTensorOpFactory
CFlotationCalvingModel	Calving model which removes all floating ice
CFortranInterfaceBasalFriction
CfortranInterfaceFlux	Class which takes an input fortran array
CFortranInterfaceIBC	Physical/domain initial and boundary conditions
CGaussianBumpFriction	Basal friction with a gaussian bump centred on b
CGaussianFunction
CGaussianFunctionX	1D Gaussian hump
Cgdalxytolatlon
CGroundingLineLocalizedFlux
CHotspotFlux
CHumpIBC	Physical/domain initial and boundary conditions
CIceBCFuncWrapper	This BCFunction simply wraps a BCFunc
CIceDivideCompGridVTOBC	Apply ice divide conditions along one boundary
CIceInternalEnergyIBC	Common virtual base class for internal energy transport IBC
CIceNonlinearViscousTensor	Implement NonlinearViscousTensor for typical (velocity-depenendent) ice rheology
CIceThermodynamics	Common function for thermodynamics, including transport within columns
CIceThicknessIBC	Physical/domain initial and boundary conditions for ice-sheet problems
CIceVelBCFunction	BCFunction-derived class to handle velocity-solve BC's
CIceVelocitySolver	Abstract class to manage the nonlinear solve for the ice-sheet momentum
CInclinedPlaneFunction
CIntFineInterp	Replaces fine level BaseFAB<int> data with coarse level data
CInverseIceVelocitySolver	Abstract subclass of IceVelocitySolver that supports inverse velocity problems
►CInverseVerticallyIntegratedVelocitySolver	Implementation of InverseIceVelocitySolver for the vertically integrated (SSA,SSA*,L1L2) stress models
CConfiguration	Data read through ParmParse
CISMIP6OceanForcing
►CJFNKSolver	Jacobian-Free Newton Krylov (JFNK) solver for the nonlinear ice-sheet/shelf momentum equations
CConfiguration
CKatzBedrockElevation
CKnownVelocitySolver
CL1L2ConstitutiveRelation	Implemnets ConstitutiveRelation to give the effective viscosity in the L1L2 stress model
CLevelDataBasalFriction	BasalFriction that computes $\beta^2$ from data on a uniform grid
CLevelDataIBC	Class LevelDataIBC stores initial topography and thickness data on a single levels and imposes either periodic or reflection boundary conditions
CLevelDataMuCoefficient	MuCoeffcient that computes $\phi$ from data on a uniform grid
CLevelDataSurfaceFlux
CLevelDataTemperatureIBC	Physical/domain initial and boundary conditions
CLevelSigmaCS	Basic Sigma fourth-order coordinate system on an AMR level
CLinearizedVTOp
CLinearRealFunction
CMarineIBC	Physical/domain initial and boundary conditions
CMaskedCalvingModel	Calving model which uses a masked input to enforce shelf collapse
CMaskedFlux	Applies a different surface flux depending on the mask
CMaximumExtentCalvingModel	A calving model which enforces a maximum extent of the ice shelf
CMelangeIceObserver	Contains an AMRMelange, responds to changes in the ice sheet state
CMelangePhysIBC	PhysIBC for the melange model
CMISOMIPBedrockElevation
CMuCoefficient
CMultiLevelDataBasalFriction	BasalFriction that computes $\beta^2$ from data on a non-uniform grid
CMultiLevelDataIBC	Class MultiLevelDataIBC stores initial topography and thickness data on multiple levels and imposes either periodic or reflection boundary conditions
CMultiLevelDataMuCoefficient
CMultiLevelDataSurfaceFlux
CMultilevelIceVelOp
CNaturalCompGridVTOBC	Apply natural conditions along one boundary
CNoCalvingModel	Simplest calving model : don't do anything
CNonlinearViscousTensor
CNormalizedFlux	Normalizes any flux so that the integrated flux has a specified value
CNoSlipCompGridVTOBC	Apply no-slip conditions along one boundary
CObjectiveWithGradient	Specify operations required to carry out gradient based optimization
CPatersonRateFactor	Paterson Rate Factor
CPerEdgeCompGridVTOBC	Apply a different CompGridVTOBC along each boundary
CPetscAMRSolver
CPetscIceSolver
CPiecewiseLinearFlux	SurfaceFlux which has a piecewise linear dependence on ice thickness
CPolarStereographicCartesianToPolarTransformation
CPressureLimitedBasalFrictionRelation	Basal friction relation which satisfies Tb = min(\|Tb'\|, a*p) u/\|u\|
CProductSurfaceFlux	Class which multiplies two surface fluxes together
CProximityCalvingModel	Calve ice based on proximity to the grounding line
CRateFactor	Rate factor A(T) in (e.g) Glen's law
CRateProportionalToSpeedCalvingModel	A Calving model that provides a rate proportional to speed: the constant of proportionality can vary in x,y,t
CRealFunction
CReflectionIceInternalEnergyIBC	Partial implementation of IceInternalEnergyIBC, provides reflection (or periodic) boundary conditions
CSchoofBedrockElevation
CsingularStreamFriction	A straight or twisting ice stream of width W with a discontinous C
CsinusoidalFriction	Simple version which sets basal friction to a sinusoidal profile
CStepRealFunction
CSurfaceFlux	Abstract class defining the surface flux interface
CSymmetricInclinedPlaneFunction
CThicknessCalvingModel	A thickness-based calving model which should permit advance and retreat
CTransformation	Abstract class for co-ordinate Transformations
CtwistyStreamFriction	Simple basal friction resulting in a twisting ice stream
CUnitMuCoefficient
CUnstructuredData
CVariableRateCalvingModel	A Calving model that provides a simple rate
CVdVCalvingModel
CVerticalConductionInternalEnergyIBC	Physical/domain initial and boundary conditions
CVieliPayneBCFunction	BCFunction-derived class to handle velocity-solve BC's
CVieliPayneIBC	Physical/domain initial and boundary conditions
CzeroFlux	Simple implementation of SurfaceFlux which sets surface flux to zero
CzeroFriction	BasalFriction which sets basal friction to zero. Probably completely useless
CZwingerRateFactor	Zwinger Rate Factor