it's possible to run Qt application on a s40 phone?
In the Ovi I observe that are someapplication named "Qt ...", but I don't understand what I've to install on the phone to run a Qt application generated by Qt Creator
Qt applications are not compatible with Series 40 and Asha devices.
If I want to do an application I must use Java or are there other languages compatible with s40?
Right now Asha and Series 40 products support Java ME Midlets and Web Applications, see https://developer.nokia.com/Develop/asha/.
Older devices support Flash Lite in addition.