https://wiki.ubuntu.com/UbuntuGIS is the wiki page about Ubuntu and GIS. This page is where we coordinate the packaging of Geospatial Open Source Software for Ubuntu. Much of this work is done for us by the DebianGIS team, as packages from Debian are automatically copied into Ubuntu during the release cycle. If you want to package your GIS software for multiple releases, you might want to start with DebianGIS.
This team is dedicated to keeping Ubuntu up to date with a suite of the best Geospatial Open Source Software.