I have currently finished a presentation about XForms and how you can use XForms to create multimodal applications (according to a paper of Mikko Honkala and Mikko Pohja). Here is the Google Doc and here is the PDF file.
https://speakerdeck.com/u/tuhrig/p/xforms-xformsmm
I will post my own paper about the topic in a couple of days (or at the end of the term if I’m lazy…).
Best regards, Thomas Uhrig.