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

[detail level 12]

NAnasazi [external]
NBelos [external]
Ndetails [external]
NEpetra_Import_Util [external]
NExperimental [external]
NKokkos
NImpl	ScopeGuard Some user scope issues have been identified with some Kokkos::finalize calls; ScopeGuard aims to correct these issues
Nhwloc	Minimal subset of logical 'hwloc' functionality available from http://www.open-mpi.org/projects/hwloc/
NTSQR [external]