The Fiduciary Licensing Agreement offers copyright consolidation in order to make Free Software projects viable in the long term. FSFE has been offering this service to the Bacula project since 2006.
Under the FLA, authors assign their code to a fiduciary (in this case, to FSFE). The fiduciary then licenses all the non-exclusive rights in their own contributions back to their respective authors. Provided that there is agreement among the authors, they may decide the project's direction as they see fit. This includes the possibility to create a non-free version of their project to stand beside the free version, if they choose.
Bacula's creator and the Bacula Systems (the company behind Bacula) assure us that they would prefer for only the Free Software version to exist, but in order to fund the continued development of Bacula, they need to offer some features under a non-free license. FSFE does not endorse the existence of a non-free version, but FSFE cannot forbid authors to execute the rights granted by copyright in their own work, as long as this does not limit the scope of fiduciary's exclusive license.
In order to assure the long-term future of Bacula as a Free Software project, FSFE and Bacula have together come to an agreement on a number of provisions to formalise their commitment and make sure that all the features of the non-free version, except from a few features that depend on third party software and are incompatible with the GPL, will become part of the free version after at most five years. If Bacula Systems (or its legal successor) ceases distributing Bacula under a Free Software license for three years, FSFE will automatically obtain all the copyright in the non-free version as well (along with the Bacula trademark). Similar provisions are put in place in case FSFE ceases to exist. This way, we are making sure more Free Software is available to the public.
You can read more about FSFE's policy on the Fiduciary License Policy page.