Internal Program Version: libproxy  0.5.7

libproxy is a library that provides automatic proxy configuration
management.

Proxy autoconfiguration (PAC) requires JavaScript (which most
applications do not have), and determing the PAC script location
requires a WPAD protocol implementation, which complicate proxy
support. libproxy exists to abstract this issue and provides
an answer how to reach a certain network resource.

http://libproxy.github.io/libproxy