Darktable For Open-Source Photography
Phoronix: Darktable For Open-Source Photography
For those less than impressed by Corel releasing some professional-grade Linux photography software earlier this month, Adobe still not providing native Linux clients for their popular applications, and haven't been fond of the major open-source photography programs out there, you may want to try out Darktable...
So what advantages does it have over Digikam? Digikam has been stable for years, and I think it already has all the features you listed.
There doesn't seem to be much interest in this discussion but I'll jump in anyhow. I haven't used Darktable but I've been using digiKam for quite some time now. It has the most laughable notion of an album i can imagine - just a directory. In my mind an album is some subset of your photos that you can arrange as you like. And some photos may be on several albums. I don't want to keep copies of my photos only so I can have them in different albums. Using tags for "albums" doesn't work either because the photos are then separated into subgroups according to the directory (album) they came from. And in any case, you cannot reorder the photos to your liking. And the order is an alphabetical one, rather than by the more relevant time of the photo (try mixing photos from a Canon with photos from a Nikon). In short, digiKam has no albums whatsoever. I don't know if any other photo management program has proper albums. I'm still using digiKam because I'm too lazy to look around. Maybe I'll give Darktable a try.