kOctave is a KDE GUI for Octave; look at Octave's homepage 
if you don't know what it is. kOctave contains an editor 
with syntax highlighting and a help browser; you can work 
almost the same way as in Matlab (c), i.e. use the editor 
and execute your code from there with (F5) or press run. 
One difference is the command window, it is meant for 
"quick commands" and not a history as in Matlab you can 
add commands to the list in settings.

WWW: http://sourceforge.net/projects/koctave/
WWW: http://athlone.ath.cx/~matti/kde/koctave/