I have been looking for a good way to sync podcasts between my Macbook Pro and Asus EeePC running Lubuntu. On the Mac, I have been using iTunes and for a while I just synced the \~/music/iTunes/iTunes Music/Podcasts folder from my Mac to my netbook with BitTorrent Sync. Then I only had to download the podcasts once on my Mac, and all podcasts would be synced to the netbook. The main problem with this apporach was that there was no way of seeing wich podcasts I had allready heard/seen without either remembering its file name or opening it to check if I had allready heard/seen it. There was also no nice GUI to see the metadata for the podcasts on my netbook without opening the files in a media player.
I stumbled across gPodder, an easy to use open source podcatcher for Linux, Windows and Mac. gPodder is a program that only does podcatching, but it does it really well. It doesn't play video or sound by itself, but the user can choose any desired program to do that. There is a sync service built into the program, but I am not a fan of trusting third party servers in «the cloud», so I am not using that.
gPodder stores all its settings and all downloaded podcasts in a folder called gPodder in your user directory. The formats of the files in the folder are the same no matter which operating system you are running. This means that to keep the same settings and the same downloaded content across machines, you could just sync the gPodder folder with BitTorrent Sync from one machine to the other. The smart thing about this is that it doesn't matter if I am at my Mac or my netbook, I can now download podcasts on wichever machine and they will be available on the other machine as well.
With the same settings, syncing from one machine to the other, you are not able to choose different programs on each machine for playing your podcasts, and even if you choose the same program on the Mac and Linux machine, you will get into trouble, since they are not stored at the same place. What you need to do is set gPodder to use the «Default program» for both audio and video in the «General» tab in the «Settings» panel and change that program to whatever you like on each machine. On the Mac, mp3 files defaults to open in iTunes if you haven't changed this setting, and this is not ideal, since iTunes will, by default, add any files to its library, thus storing the same file twice on the machine.
I am using VLC as the default program for most video and sound files on both my Mac and EeePC. To set wich programs act as default on a Mac, choose a file of the desired format in the Finder, press command-I (or choose «Get info» from the «File» menu) and choose the desired program in the pull down menu on the lower left. Then click «Change all…» to make this change universal for all files of this type. On Lubuntu, just select «Default programs» from «System settings» in the Lubuntu menu and change to your desired programs. On Ubuntu, choose «System settings» from the dash or dock, then choose the «Details» settings panel and the «Default programs» tab from the menu on the left and set music and video to whatever you prefer.