The document discusses using OpenSSL to improve Tomcat performance. It describes Tomcat connectors like NIO, NIO2, and APR and how the new OpenSSLImplementation replaces the default JSSE implementation. Performance tests show the OpenSSLImplementation outperforms JSSE, with NIO and NIO2 performing similarly. Throughput is highest for all connectors with larger file sizes. The OpenSSLImplementation enables features like HTTP/2 and ALPN that improve Tomcat.