I'm mostly supporting Bacula, the open source backup and recovery package. Both for free on the project mailing lists and commercially.
Community Mailing lists
You'll find I read almost all the mail that is sent to bacula-users and bacula-devel at lists dot sourceforge.net. If you want to get support for your installation of Bacula, and do not require professional, commercial support, that's where you can find a great community with real in-depth knowledge and lots of experience.
Yes, indeed. No advertising here, though.
Well, I'm not really involved with Fedore Core. I run some test installations, and I do maintenance of Fedora Core installations, but that's about all... my contact with the Fedora Project is mostly my talk at FUDCon: Berlin 2009.