The existing topic-tools mux only allows you to route multiple incoming topics into one outgoing topic. But this package allows you to both demultiplex many-to-one connections and multiplex one-to-many connections.
This is useful during instances when you want to control multiple robots using Rviz (see multi_map_navigation).
ROS Hydro, Catkin: topic_tools, tf (see package.xml)
Clone Repo:
$ cd <catkin_ws>/src
$ git clone https://github.com/MohitShridhar/namespace_mux.git
Resolve dependencies (in Ubuntu) & Compile:
$ cd <catkin_ws>
$ rosdep install --from-paths src --ignore-src --rosdistro hydro -y
$ catkin_make --pkg namespace_mux
See wiki for more details.