@musicman I don’t know, but I could guess that #Apache #mod_ssl probably has versions because they pull in #OpenSSL, which has versioned security releases. Whenever these openssl versions become incompatible, things that hook into it, such as mod_ssl, need to release a new version that is compatible with the new one.
(I guess its rival #ApacheSSL must be completely dead now. I’ve not seen it mentioned anywhere in several years. Also not heard from is #mod_gnutls, which I used on my first self-hosted instance.)