App Engine PHP SDK  v1 rev.445
The PHP runtime is available as an experimental Preview feature.
Namespace List
Here is a list of all documented namespaces with brief descriptions:
[detail level 1234]
 Ndummy
 Ngoogle
 Nappengine
 Napi
 Napp_identity
 Ncloud_storage
 Nlog
 Nmail
 Nmodules
 Ntaskqueue
 Nusers
 Ndatastore
 Next
 Ncloud_storage_streams
 Nremote_api
 Nsession
 Nruntime
 Ntesting
 Nutil
 Nappengine_datastore_v3
 Nnet