Which way to go in Linux (Qt or KDevelop)
Which one of the IDE is good in terms of support for debugging, implementation and usabality. Qt or KDevelop?
Various duplicated:
https://stackoverflow.com/questions/86676/is-there-a-good-and-free-ide-for-cc-in-linux
what's the best stable editor & compiler for c++ with gui & under linux?
https://stackoverflow.com/questions/211924/best-development-ide-for-linux-closed
Some of which have already been closed.
Answer
You seemed to be confused. Qt is a C++ toolkit. KDevelop is an IDE.
From your comment I see that you meant Qt Designer. Designer is not an IDE; it is just an application for graphically creating user interfaces. It can't compile code, debug, or do any of the other things an IDE does.
The KDevelop IDE actually embeds Designer into itself, so this clearly isn't a "one or the other" type situation.
Of course a third possibility is that you were talking about Qt Creator, the IDE that was recently released as beta by Qt Software. If that's the case, then I would just encourage you to try them both out and see which you prefer. They take different approaches and the better option would be based almost entirely on personal preference.