[FusionDev] Is there a way to detect which window manager is running?

[Nick Bauermeister]

This may be a little off topic here but does anybody know if there's a
way to detect the current window manager?

I'd like to know because I want to write a script which uses xfwm4.
Since it doesn't have a --replace option, you have to kill the current
WM to use it.

Regards,
Nick