During this week, we have merged in patches to allow building command-line binaries under FreeBSD.
For building you need to install git, cmake, Boost, MiniUPnPc and OpenSSL. The bundled MiniUPnPc library does not support FreeBSD yet. Currently only “develop” branch supports building under FreeBSD. We are planning to support other BSD variants, but it will take some time to merge and test patches to build system and sources.