It starts with the message "Unknown or ambiguous terminal name 'aqua'". And issues the message "Terminal type set to 'unknown'". The gnuplot command show term gives: terminal type is unknown. I also tried plotting but no plots appear. I used otool -L gnuplot to see if gnuplot is linked to Aquaterm (there is an Aquaterm and a libaquaterm.dylib embedded in the Gretl.app). Apparently not. But when I plot a something from within Gretl's main window I get a nice plot. So what is Gretl asking gnuplot to do? I've also made a gnuplot script and that also doesn't seem to plot anything. What's going on? Berend BTW: window switching now working with no problems. Thanks a lot for this. Gretl quartz is a pleasure to use now and a lot faster in starting up than the X-version.