Compositing

Compositing allows you to make some fancy effects with window transparency.

Windows™ Vista and Windows 7 introduced Compositing.

This allows you to make some fancy effects with window transparency. If you want a semi-transparent window in GDC, you may use the "blurBackground" style attribute:

<Style name="Window.semitransparent">
  <StyleAttribute name="blurBackground" value="yes"/>
</Style>

See the classic demo application with a semi-transparent background, running on Windows 7. This will not work on "old" windows (XP and before), but may work on Linux™ depending on the windows manager capabilities.