A proxy auto-configuration (PAC) file defines how a web browser can automatically choose an appropriate proxy server for fetching a given URL.

The file is based on Javascript, uses relatively simple syntax and modern browsers such as Internet Explorer, Firefox, Opera, Chrome and Safari support the PAC standard.

Voir:

• Web Proxy AutoDiscovery protocol (WPAD)
• http://findproxyforurl.com/ A Proxy Auto-Configuration Resource