Dave,

I do some work in Qt. Primarily helping to port Lmms to Qt4.  I am now working on a successor. This host is in Qt4 and uses lv2 as the primary plugin api. I desire embedded plugins, so this topic is close to my heart.

Anyways, I would name the URI after Qt4 instead of simply Qt. Qt breaks some ABI compatibility in major releases. So, including the 4 in the name should protect us when 5 is released.

Regards
Paul