Here is a list of all namespaces with brief descriptions:

[detail level 123]

N__cxxabiv1 [external]
N__gnu_cxx [external]
N__gnu_debug [external]
N__gnu_internal [external]
N__gnu_parallel [external]
N__gnu_pbds [external]
N__gnu_sequential [external]
Nabi [external]
NCairo
▼NGdk
NCairo
NGraphene	Types for graphic libraries
NGio
▼NGlib
NContainer_Helpers
▼NGtk
NAccelerator	Utilities for keyboard accelerators
Nsimd_abi [external]
Nstd [external]