Here is a list of all documented namespaces with brief descriptions:

[detail level 123]

Ninviwo
Nanimation
Nbuffertraits
Ncimgutil
Ncolor
Ncolorbrewer
Ncsvfilters
Ndataframe
Ndataframefilters
Ndispatching
Nfilter
Neigenutil
Nfilesystem
Ninviwopy
Nkind	A type trait to connect data classes to representation classes of different kinds
Nlog
Nmeshutil
Nplot
Npool
Ndetail
Npyutil
Nstatsutil
Nswizzlemasks
Nutil
Nutilcl
Nutildoc
Nutilgl
Nutilqt
Nxml
Nstd	STL namespace