should I use openssl or LibreSSL on OSX?
Historically OpenSSL has more security vulnerabilities than LibreSSL. According to Stackexchange, from the 6 critical vulnerabilities in OpenSSL since the fork none affected LibreSSL. People also find LibreSSL easier to use. LibreSSL replaces OpenSSL OS X since 10.11, so there is no need to switch back to OpenSSL for sure. Why do you ask?