Varnish was written from the ground up to be a high performance caching reverse proxy. (Caching Proxy Server). Varnish was designed as an HTTP accelerator. Varnish is focused exclusively on HTTP, unlike other proxy servers that often support FTP, SMTP, and other network protocols. https://en.wikipedia.org/wiki/Varnish_(software) open-source

https://www.varnish-software.com/

older notes

http://varnish.projects.linpro.no

2010: can't do SSL (directly)