In Ubuntu/Linux Mint, you can easily apply the Aero Glass effect on active windows like on Windows 7. If you are interested in enabling this visual effect on the window title bar of Ubuntu 12.04 or Linux Mint 13, you can follow the instructions in this tutorial. If you have an alternative method for doing this, you can mention it below.
Let's first change the title bar transparency for all Ubuntu active windows. The default transparency value is 1 and in this tutorial we will set it to 0.3, but you can increase/decrease it slightly if you want. To do this, open the terminal and run this command (transparency value is highlighted in red):
gconftool-2 --type float --set /apps/gwd/metacity_theme_active_opacity 0.3
After running this command, you will notice that the title bar for the current active window will be transparent. We need now to apply the blur effect with the help of CompizConfig Settings Manager. To install it in Ubuntu 12.04/Linux Mint 13, run this command:
sudo apt-get install compizconfig-settings-manager
Start it and open the Effects section, then enable the "Blur Windows" option:
Close now the CompizConfig Settings Manager. You have now enabled the Aero Glass effect under Ubuntu/Linux Mint. If you want to disable it and restore default settings, check the off the "Blur Windows" option you have already enabled, then run this command to disable title bar transparency:
gconftool-2 --type float --set /apps/gwd/metacity_theme_active_opacity 1.0