WINEPREFIX
If set, the contents of this variable is taken as the name of the directory where Wine stores its data (the default is $HOME/.wine). This directory is also used to identify the socket which is used to communicate with the wineserver. All wine processes using the same wineserver (i.e.: same user) share certain things like registry, shared memory, and config file. By setting WINEPREFIX to different values for different wine processes, it is possible to run a number of truly independent wine processes.
export $WINEPREFIX=wine_for_fiddler wine fiddler.exe
export $WINEPREFIX=wine_for_nonfiddler wine nonfiddler.exe