However, MOST of the code developed by Bacula Enterprise are in the form of Plugins (Vmware, Databases, etc.) (...) that CAN'T be considered derivations / modifications of the original Bacula Source code.

Bacula plugins are derived work of Bacula code. Please read my discussion with Kern about 2010 when I start developing a PostgreSQL plugin for Bacula:

Kern Sibbald:

"(...)

There are varying opinions on whether or not a plugin is a derived work or
not, but it is and has always been the opinion of the FSFE that a shared
object (as is the case for Bacula plugins) is a derived work, which means
that it must have the same license (or at least one that is compatible).

I personally am probably a bit more open to different possibilities, but I
firmly believe that if you are extending Bacula with a plugin, you should
give back to the community by providing it with your source code.

(...)"

So, I extended a Bacula with a plugin and released it with AGPLv3 license. Releasing a plugin with a different license is a bit complicated because Bacula allow plugins with a specific licenses only:

fd_plugins.c:1160:

   if (strcmp(info->plugin_license, "Bacula AGPLv3") != 0 &&

       strcmp(info->plugin_license, "AGPLv3") != 0) {

      Jmsg(NULL, M_ERROR, 0, _("Plugin license incompatible. Plugin=%s license=%s\n"),

           plugin->file, info->plugin_license);

I'm not talking here about Bacula Enterprise because it has a different license.

best regards

--

Radosław Korzeniewski