There is now an active effort to include a QT-only (no KDE) based IDE for Octave that is part of the main Octave source code. I recommend that you build and test that version of an IDE, as it will be the most supported option going forward.
The octavede is a development environment for the Octave mathematical software package. Octave normally is run in a terminal. Octavede provides an GTK/X11 application that provides functionality similar to other mathematical software packages.