Xshell offers a transparency setting.

To Set Window to Appear Transparent:

1. Select [Transparent] from the [View] menu.
2. Open the Options dialog box.
3. Set transparency in the [View] tab.
4. Set [Opacity]. The smaller the opacity is, the more transparent the Xshell window becomes.
5. If [Make window opaque on mouse over] option is selected, Xshell window is displayed opaque while mouse is over the window even when it is set to display Xshell window transparent.
6. If [Always on Top when it is transparent] option is selected, Xshell window is displayed at the top of all windows.