The interoperability layer between creative FOSS applications - GitHub - CreativityOpen/OpenCreativity: The interoperability layer between creative FOSS applications
This is definitely something that's needed, so thanks for taking the initiative to start something :)
Just to note, your front page suggests darktable as an Illustrator replacement - whereas I would have said Inkscape is the Illustrator replacement (they are both vector graphic editors) and that Darktable is for processing raw digital photographs.