These are precompiled versions of OpenSSL.
Naming convention: -
v1_1_1g-macos_10_15 for macOS 10.15 and later v1_1_1g-mint_19_03 for Linux Mint 19.3
SecureSockets 1.1.1 and later use a different approach to adopting openSSL. It is no longer necessary to modify the openSSl sources, but instead use CopensslGlue to provide the glue code.
v1_1_0-macos_10_12