Update Parent

Here's an example:

svn checkout http://svn.codehaus.org/mojo/tags/xmlbeans-maven-plugin-2.3.1 xmlbeans-maven-plugin
cd xmlbeans-maven-plugin
mvn versions:update-parent

Which produces the following output:

[INFO] Scanning for projects...
...
[INFO] ------------------------------------------------------------------------
[INFO] Building Maven XML Beans Plugin
[INFO]    task-segment: [versions:update-parent]
[INFO] ------------------------------------------------------------------------
[INFO] [versions:update-parent]
...
[INFO] artifact org.codehaus.mojo:mojo: checking for updates from codehaus.org
[INFO] artifact org.codehaus.mojo:mojo: checking for updates from central
[INFO] Updating parent from 14 to 17
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESSFUL
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 24 seconds
[INFO] Finished at: Thu Aug 14 15:17:04 IST 2008
[INFO] Final Memory: 9M/166M
[INFO] ------------------------------------------------------------------------

You can restrict the versions to be considered:

mvn versions:update-parent "-DparentVersion=[14,16)"

Note that, by default, -SNAPSHOT versions are ignored. You can force snapshots to be included with the allowSnapshots parameter:

mvn versions:update-parent -DallowSnapshots=true