Phpyke is a full-featured IDE primarily aimed for PHP development, but supporting other major languages as well. It is created using Qt toolkit in C++ with editor based on QScintilla.
NoteCase is portable (Linux, Win32) hierarchical notes manager (aka outliner) coded in C++ using GTK+ toolkit. Project is inactive as of 2008/12/09, read more at: http://factoriel.blogspot.com/2008_12_01_archive.html