Here is a list of all modules with brief descriptions:

Nambm
Nbc
Nbodyforce
Ncalc_collision_wall
Ncalc_gr_boundary
Ncdist
Ncg_init_namelist
Ncheck
Ncheck_data_cg
Nchischeme
Ncoeff
Ncompar
Nconstant
Ncont
Ncorner
Ncut_cell_preproc
Ncutcell
Ndashboard
Ndbg
Ndbg_util
Ndebug
Nderived_types
Ndes_allocate
Ndes_bc
Ndes_cluster
Ndes_rxns
Ndes_thermo
Ndes_thermo_cond
Ndesgrid
Ndesmpi
Ndesmpi_wrapper
Ndiscretization
Ndrag
Nenergy
Neos
Nerror_manager
Nexit
Nfldvar
Nfun_avg
Nfunction3
Nfunctions
Nfunits
Ngenerate_particles
Ngeometry
Nghdtheory
Ngridmap
Nic
Nin_binary_512
Nin_binary_512i
Nindices
Ninterpolation
Nis
Niterate
Nkintheory
Nleqsol
Nlist
Nmachine
Nmain
Nmfix_netcdf
Nmfix_pic
Nmflux
Nmms
Nmpi_comm_des
Nmpi_funs_des
Nmpi_init_des
Nmpi_node_des
Nmpi_pack_des
Nmpi_unpack_des
Nmpi_utility
Nmulti_sweep_and_prune
Noutput
Noutput_man
Npair_manager
Nparallel
Nparallel_mpi
Nparam
Nparam1
Nparse
Nparticle_filter
Npgcor
Nphysprop
Npic_bc
Npolygon
Nprogress_bar
Nps
Npscor
Nqmom_kinetic_equation
Nqmomk_bc
Nqmomk_collision
Nqmomk_fluxes
Nqmomk_parameters
Nqmomk_quadrature
Nqmomk_tools
Nquadric
Nrandomno
Nrdf
Nread_input
Nread_res1_des
Nread_thermochemical
Nreinit
Nresidual
Nresize
Nrun
Nrxn_com
Nrxns
Nscalars
Nscales
Nsendrecv
Nsendrecv3
Nsendrecvnode
Nsolids_pressure
Nstep
Nstiff_chem
Nstiff_chem_dbg
Nstiff_chem_maps
Nstiff_chem_stats
Nstl
Nstl_dbg_des
Nstl_functions_des
Nstl_preproc_des
Nsweep_and_prune
Ntau_g
Ntau_s
Ntime_cpu
Ntoleranc
Ntrace
Nturb
Nur_facs
Nusr
Nusr_prop
Nusr_src
Nutilities
Nvisc_g
Nvisc_s
Nvshear
Nvtk
Nvtp
Nwrite_res1_des
Nxsi