Typically, I have been using commercial programs, such as Articulate or Captivate to take a fully animated powerpoint presentation with audio and port it to HTML5 for use in LMS systems. Moodle is a very popular open source LMS for use in presenting e-learning courses.
I think coming up with a way to create a presentation with interaction for e-learning within Impress that can then be converted by Impress to a set of HTML5 pages would be a real coup and allow e-learning designers worldwide to create material that runs on tablets, phones, and computer screens.