dpkg is the underlying software used by all Debian based distributions (including Ubuntu of course) to install/upgrade/remove Debian packages (.deb files). The dpkg-dev part is used to build Debian binary packages out of the Debian source packages provided by package maintainers. NOTE: While there are 2 dpkg maintainers, currently the money goes only to Raphael Hertzog since Guillem Jover was not interested to have his share. More