Here is a list of all namespaces with brief descriptions:

[detail level 123]

▼Nrclcpp
Nallocator
Nany_service_callback
Nany_subscription_callback
Ncallback_group
Nclient
Ncontext
▼Ncontexts
Ndefault_context
Nevent
Nexceptions
Nexecutor
▼Nexecutors
Nmulti_threaded_executor
Nsingle_threaded_executor
Nfunction_traits
Ngraph_listener
Nintra_process_manager
Nmapped_ring_buffer
▼Nmemory_strategies
Nallocator_memory_strategy
Nmemory_strategy
Nmessage_memory_strategy
Nnode
Nnode_interfaces
Nparameter
Nparameter_client
Nparameter_service
Npublisher
Nrate
Nservice
▼Nstrategies
Nmessage_pool_memory_strategy
Nsubscription
Ntimer
Ntype_support
Nutilities
Nstd