XFig

XFig is not young. It's not beautiful either. It is still in use though. Even on Windows, there are people setting up cygwin only to get xfig. And that is because it has one killer feature. Export to Postscript/LaTeX in a way that lets latex replace the text in the drawing. That way the font and text size etc are consistent with the rest of the latex document. And you can add LaTeX text relatively easy and comfortable to your drawing too. Usability wise XFig is a killer... Even though it is possible to work fast with it thanks to keyboard shortcuts and quite advanced functions below the gui. I wish there was something like this available in a modern graphics application like Krita. Looks like I will have to learn getting along with XFig...