Since starting photography I've been using Dark Table to edit, catalogue and tag my pictures. Dark Table isn't the easiest tool to use, it has some quirks but in the 18 months I've been using it I've mostly got used to these. The odd way navigating to filters works, using the scroll wheel to move up and down the filter list is frustrating, the app window doesn't fit on the Mac Book 13" so you have to drag the window round when wanting to performing certain actions.
With all this I've decided to move over to RawTherapee for image manipulation and Digikam for cataloguing and tagging. I've not really looked at Digikam yet but I'm hopefully that any tags I've added via Dark Table are not part of the sidecar file but written to the image file itself.
I now need to learn RawTherapee, it should be a little easier than Dark Table. I have a decent understanding of photo editing, I just need to learn RawThrerapee itself.