Resources

• Need for Speed – How to Improve your Website Performance
• High performance .htaccess

Client side

• Minification
• GZIP
• Caching

Server side

• PHP APC
• nginx
• Varnish
• Squid
• HAProxy
• Memcached

Nice article on Quora: What is the fundamental difference between varnish and squid caching architectures?

A comparison between Apache and nginx on wikivs: Apache vs nginx