I transferred this repository from my personal github account to ros-drivers, since a number of other groups now depend on it. The corresponding release repository is in ros-drivers-gbp.
Jim Rothrock has volunteered to help maintain those messages. That's good, because he maintains a number of related Ackermann steering packages, while I am currently not working on those kinds of vehicles these days.
Those messages have been stable for the several years now. Please respond on this mailing list if you have comments or suggestions.