Is there any way to make Emacs partially transparent in kde4? I tried some of the solutions proposed online, but none of them had any effect at all; I suspect it might be an issue with kde, but I am not actually sure.
Have you tried setting the application-specific KWin settings for Emacs? If you right-click the title-bar of Emacs, and select Advanced->Special Application Settings, you should get app-specific settings which will be used whenever Emacs opens. I selected "Active Opacity %" in the "Preferences" tab, set it to 75, and selected "Force" in the drop-down. Emacs now comes up with 75% opacity whenever it launches.
Note: I'm using KDE 4.4.
Edit: Just for reference: a brief search for Emacs + transparency came up with this. I didn't have any luck with Emacs' settings either.