I'm having a difficult time understanding where the Forrest
application ends and where the data for the site begins.  Is there
always a one-to-one relationship between the Forrest app and a site? 
In other words can the app be used to operate on multiple sites or is
the site configuration so inter-twined with the application that one
needs separate "instances" of Forrest for each site (changing
"$FORREST_HOME" for each site)?

In terms of Forrest directory structure, I think here's what I'm asking:

Instead of:
..\src\documentation

..\src\site1-documentation
..\src\site2-documentation
..\src\site3-documentation

Where site1, site2, and site3 are totally different web sites.  I
guess the command line would somehow have to support an extra
parameter naming the site to be built/run.

Any help in understanding this would be appreciated.

Thanks,
--tim