OpenSSL is the more common of the two in our index: it runs on 330 websites against 76 for Google PageSpeed, and 3 sites use both. Counts come from real scans, not vendor claims.
Google PageSpeed is a family of tools designed to help websites performance optimisations.
OpenSSL is a software library for applications that secure communications over computer networks against eavesdropping or need to identify the party at the other end.
3 sites run both Google PageSpeed and OpenSSL. That is 4% of the sites using Google PageSpeed, the smaller of the two.
Want to know which one a particular site uses? Look it up and see its whole stack, or compare two sites side by side.