e.g. http://www.phabricator.com/docs/phabricator/article/Arcanist_User_Guide.html
-It runs on Linux, Mac OS X (see Arcanist User Guide: Mac OS X), and Windows (see Arcanist User Guide: Windows).
+It runs on FreeBSD, Linux, Mac OS X (see Arcanist User Guide: Mac OS X), and Windows (see Arcanist User Guide: Windows).
http://www.phabricator.com/docs/phabricator/article/Installation_Guide.html
Mac OS X is an acceptable flavor of Linux.
+FreeBSD is also fine.
(I'd write "FreeBSD and Mac OS X are acceptable flavours of Linux" but that will upset some FreeBSD people.)
I could contribute an install_freebsd.sh
To get it going basically all I had to do was
% sudo pkg install php5 php5-curl php5-json