pacparser is a library to parse proxy auto-config (PAC) files. Proxy auto-config files are a vastly used proxy configuration method these days. Web browsers can use a PAC file to determine which proxy server to use or whether to go direct for a given URL. The idea behind pacparser is to make it easy to add PAC file parsing capability to any program (C and Python are supported right now). It comes as a shared C library and a Python module that can be used to make any C or Python program PAC scripts intelligent. Some very useful targets could be popular Web software like wget, curl, and python-urllib.