I just committed my first implementation of a text producer based on QT:
Comments are welcome.

I copied the producer_pango properties/arguments as well as I could. There are two exceptions:
1) Obviously, I can't implement the pango markup property. So the markup property is excluded from qtext.
2) I see an undocumented feature in producer_pango to load text into keyframes from a .mpl file. I didn't carry that over because I don't know the use case. But it could be easily ported if necessary.

My plan is to next modify producer_count and filter_dynamictext to use qtext first and revert to pango if qtext is not found. if I do that, should I move those two files out of the GTK folder? If so, to where?

I would also like to add qtext as a second service for ".txt" files in loader.dict - but i thought I better check with you first.

Let me know your thoughts.