Here is a list of all namespaces with brief descriptions:

[detail level 12345]

Nactivemq	Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements
Ncmsutil
Ncommands
Ncore
Nkernels
Npolicies
Nwireformat
Nopenwire
Nmarshal
Ngenerated
Nutils
Nstomp
Nstate
Nexceptions
Nio
Nlibrary
Nthreads
Ntransport
Ncorrelator
Nfailover
Ninactivity
Nlogging
Nmock
Ntcp
Nutil
Ncms	Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements
Ndecaf	Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements
Ninternal
Nio
Nnet
Nfile
Nhttp
Nhttps
Nssl
Nopenssl
Ntcp
Nnio
Nsecurity
Nprovider
Ncrypto
Nutil
Nconcurrent
Nnet
Nssl
Nsecurity
Nauth
Nx500
Ncert
Nlang
Nexceptions
Nio
Nnio
Nutil
Ncomparators
Nconcurrent
Natomic
Nlocks
Nlogging
Nzip
Nstd