Return to Revisions

First of all, you're mixing two things that are completely independent from each other:

• (One for all or one for each) SCM repository and
• Maven projects with their versioning.

Note that sub-module projects that use a <parent> don't necessarily have to use the parent POM version that's the current one in the SCM repository, e.g.:

Root POM

  <groupId>my</groupId>
  <artifactId>root</artifactId>
  <version>2.0.0-SNAPSHOT</version>

Lib1 POM

  <parent>
    <groupId>my</groupId>
    <artifactId>root</artifactId>
    <version>1.2.3</version>
  </parent>

  <groupId>my</groupId>
  <artifactId>lib1</artifactId>
  <version>4.5.6-SNAPSHOT</version>

is perfectly fine since my:root:1.2.3:pom will be resolved from the (local or remote) Maven repository (if it has been installed/deployed there previously).

Root Project Version

The meaning of the of the version number of the root project (with <packaging>pom) is the same as for any other Maven project:

• x.y.z-SNAPSHOT version while you add/remove/change things in your POM and test them,
• x.y.z release version if every work is finished, tested thoroughly and hence ready to be released into the wild.

It's entirely up to you which change increases the major, minor or patch version number.

Distribution Package Version

You don't have to pick a version from (one of) the components. The things mentioned at the beginning (independence of SCM repository and Maven projects) and under Root Project Version above apply here, as well.