FVWM: Is FVWM mult-threaded?

[msibley]

Howdy, 

I've got a problem with a script. I'm Pipereading a menu, which queries
an environment variable in FVWM using FvwmCommand to determin how to
output the menu data. 

So it goes: FVWM->Piperead->Script->Fvwmcommand

FVWM appears to be blocking. (The script doesn't block, and appears to
timeout waiting on Fvwmcommand) 

So FVWM is not multithreaded? 

Thanks!