Project genmsg exists in order to decouple code generation from ROS .msg & .srv
format files from the parsing of these files and from impementation details of
the build system (project directory layout, existence or nonexistence of
utilities like rospack, values of environment variables such as
ROS_PACKAGE_PATH): i.e. none of these are required to be set in any particular
way.

Homepage:
http://www.ros.org/wiki/roscpp
