Here is a list of all namespaces with brief descriptions:

boost
boost::details
boost::stack_trace
OFX
std
tuttle	Global namespace of the project
tuttle::common
tuttle::common::details
tuttle::exception
tuttle::host	Library for host
tuttle::host::attribute
tuttle::host::core	All main class of the host
tuttle::host::exception
tuttle::host::graph	Graph work
tuttle::host::graph::detail
tuttle::host::graph::visitor
tuttle::host::io
tuttle::host::memory
tuttle::host::ofx	OpenFX wrapping to communicate with C API
tuttle::host::ofx::APICache
tuttle::host::ofx::attribute
tuttle::host::ofx::imageEffect
tuttle::host::ofx::interact
tuttle::host::ofx::property
tuttle::ofx
tuttle::ofx::imageEffect
tuttle::plugin
tuttle::plugin::color
tuttle::plugin::color::ColourTemp
tuttle::plugin::color::GradationLaw
tuttle::plugin::color::Layout
tuttle::plugin::color::Premultiplication
tuttle::plugin::color::Primaries
tuttle::plugin::exception
tuttle::plugin::interact
tuttle::plugin::overlay
tuttle::plugins	Library for plugins
tuttle::test