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Well, "we" (as the openvpn team) don't do MacOS binaries - because it's 
basically easy to compile it yourself :-) - do git clone, autoreconf -vif, 
make (possibly compiling and installing LZO first).  

The resulting openvpn binary can then be used directly or copied into the 
Tunnelblick bundle, and it will get used by the GUI...