What is the best IDE for developing a C++ application targeting Symbian UIQ-based phones like p990 and p1?
So far I have come across Carbide C++ which seems good but I am not sure if it supports UIQ (maybe it only supports S60 platform) and if it's the best option.
Yes Carbide C++ is the right answer. UIQ SDK availability is another story, however. After the bankruptcy of UIQ the rights to UIQ were locked down, and have not been contributed to Symbian Foundation.
As far as I know there is no "legitimate" way to get hold of the SDK. On the other hand, there is no rightsholder who will chase you down if you do...