apt-listchanges is a tool to show what has been changed in a new version of a Debian package, as compared to the version currently installed on the system. It does this by extracting the relevant entries from the Debian changelog file, and the NEWS.Debian file.
It can be run on several .deb archives at a time to get a list of all of the changes that would be effected by installing or upgrading a group of packages. It can be configured to do this automatically during upgrades using apt.
We mentioned apt-listbugs a while back. Possibly even more useful than that is apt-listchanges. The beauty of Apt is how packages like apt-listchanges and apt-listbugs cleanly hook into the system and do the right thing at the right time. When you run apt-get -u upgrade, apt-listbugs and apt-listchanges kicks into action and lets you know what you can expect before you give the final go-ahead.
More information on this package can be found on the Debian web site.
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