First I looked into several animation film companies and tried to get to know more about their animation workflows. Surprisingly there are many similarities:
The general workflow is storyboard on paper, put the storyboard into a movie, make the story board in maya with the actual characters (blocked out animation), give the animation more smoothness, then add detail to the face and hands, polish, polish, polish.
Disney & dreamworks animate in Maya, dreamworks also does color grading in Lustre. Their in-house animation tools would therefore be interesting to look into some more, as they’re most likely Maya enhancements.
Pixar used to have Maya several years ago but are now using their own software named Mindy (or Marionette, with Gepetto for facial animation), which is a very minimal looking piece of software showing a timeslider with sound and a viewport with some menus. Also it has hundres of controls, and it appears very little animating is done in the viewport, but only using curves and control sliders.
Best reference is this video.
I also looked at some Weta Digital papers but the majority of it is simulation focussed and has nothing to do with user friendly animating and are far too complex to be in the scope of the tools I’m willing to create; also looking at the timeframe of graduation & specialization.