glendoso,
The MyEclipse Visual Swing Designer (Matisse) is available only for Windows and Linux. It is not available on Mac owing to the compatibility issues.
Even though Matisse is available as optional component in Windows and Linux, it is long deprecated and we recommend working with the Swing and SWT designers of WindowBuilder, which is shipped with MyEclipse and installed by default: https://www.genuitec.com/products/myeclipse/learning-center/gui-design/swtswing-designer-installation/
Please also refer to this tutorial for detailed help with SWT/Swing Designer : https://www.genuitec.com/products/myeclipse/learning-center/gui-design/myeclipse-swtswing-designer-overview/
Hope this helps. Please let us know if you have any questions.
–Swapna
MyEclipse Support