firefox help

[Bill Schmitt (SW)]

I'm a newbie who is trying to install a recent release of firefox under 
version 4.9 of  FreeBSD. I downloaded the installer (for linux since 
there doesn't appear to be a FreeBSD version, yet) from Mozilla, but 
when I try to execute it, I get the message "error while loading shared 
libraries: libgtk-x11-2.0.so.0". I've tried finding a package that 
includes this library, but haven't been successful. Can somebody help?