For me the biggest difference is workflow. darktable is better att handlig multiple files, multiple output sizes, metadata etc.
RT is more a tool for custom crafting a new demosaiced master file.
I quite like both the denoise and sharpening of darktable but RT has many nice little tricks and I use it for files that require extra care.
I look forward to the locallab build in Rawtherapee becoming part of the main build. I find it very easy to make quick local adjustments without having to use masks.
Overall I think both Rawtherapee and Darktable are great programs. Darktable looks a bit more polished and has masks but Rawtherapee has better noise reduction and dcp colour profiles. I really like the HaldClut film simulations in RT.
At the moment RT and dt have many overlaps and many differences in approach, but I would not say one is better than the other.
One thing to consider though is that (from what I can see) dt is currently largely developed by 2 people only, while RT has the benefit of having at least 5 people actively involved. This does provide more opportunities for RT to grow than it does for dt. My message in general would be: If you see something missing in either software and you know how to contribute, please do so 
I looked at DT a few years ago, then again just recently (within the last few months). I was amazed at how much it had matured in that time. About the same time, I also started playing around with RT and was pleased with the results I was able to get. There’s a learning curve (like anything else), but I’m finding it’s well within my grasp if I spend the time to play around with the controls and do my homework with it. I don’t know if DT is any better or worse (it’s just different), but for now I’m using RT for my serious editing work.
I don’t even really see them as the same type of tool.
RT feels like a raw processor & non-destructive image editor
DT additionally has an integrated dam, printing, local adjustments, etc
The difference is workflow related for me. My workflow, is much more aligned with a product with an integrated DAM so I have switched to DT.
Conversely, if you don’t want/need the integrated DAM, it will just get in your way when you use DT as a standalone editor. You can just pop the file open in RT and make the changes without having to worry about importing it.
it would be wonderful if the two applications found together: RawTable or DartTherapee. Then you can use the best filters from both worlds. Wonderful.
micha
I hope not in my lifetime, and I think there is no danger for this to happen anytime soon. Good solutions already get transferred, in some way, when it is doable and useful.
Edit: PhotoFlow is interesting.
It is FLOSS, so code can be shared.
It can, but in order to have a cross-product non-destructive workflow wouldn’t that mean that both products would have to fully implement all the adjustments from the other product?
You can already use both products together if you render the adjustments from one and send it to the other.
I would love to see a fully non-destructive workflow between the two but it seems impractical.
You can actually control sliders in RT with mouse wheel if you press shift down.
Thank you 
I use Darktable for a few month now and only had a brief look at Rawtherapee because I came across a *.pp3 file and even hat to look up what software that belonged too.
What I noticed about RT:
Is it possible to use both? Like, starting a RAW with DT, saving it as TIFF and do something with RT or will I lose quality.
(For my scanned Tiff I will probably use GIMP)
I’ve been a born again RawTherapee fan for several years now. For what ever masking I do I edit the same image three or four times with RawTherapee and ship the results off to Gimp. Once Gimp has those 3 or 4 versions coming from RawTherapee I do layer masking (when called for) and detail tweaking–using Gimp. I’m a happy camper.
But I recently (because of a thread here) found the wonderful Harry Durgin videos on youtube. And he uses Darktable. So now I’m trying to learn new tricks.
I wouldn’t try to make a cost benefit analysis between Darktable and RawTherapee without at least becoming familiar with Harry Durgin’s work first. The following link is just one of many.
What is this feature? is it in the rawpedia?
From the 5.4 release notes:
New histogram matching tool, to have RawTherapee automatically adjust the image for you to match the out-of-camera look with a single click of a button.
where is this witchcraft 
I gotta find this
I haven’t written that article yet, but so far it’s mentioned here:
http://rawpedia.rawtherapee.com/Sidecar_Files_-_Processing_Profiles#Defaults
@Morgan_Hardwood @paperdigits okay thanks! so otherwise it’s just the button under Saturation in the RGB section that says “Auto-Matched Tonecurve”. I never use it so I never really bothered to read up on it. Always sortof assumed it would be an auto-levels and curves thing where RT decides what would look good Well now that I know I was wrong, and know what it does, odds are I’ll probably still use my own curves, but I’m gladder for knowing 
Thanks guys for the effort; this is another great tool which gives us the freedom of choice which Lightroom does not.
I find the auto matched tone curve invaluable when I don’t want to do a lot of editing.
@paperdigits now does the function also cover RGB? - probably not; but could it and to have it match up to the tones of another image of your choice.
I know I’m going pretty far out with this; but I’m picturing applying some editing to the raw file (only curves and RGB curves); then save as JPG and have RT match it