"Internet Routing: It's a program (well, a daemon, as you are going to discover in a moment) which works as a dynamic router in an Internet type network (that is, in a network running either the IPv4 or the IPv6 protocol). Routers are devices which forward packets between interconnected networks in order to allow hosts not connected directly to the same local area network to communicate with each other. They also communicate with the other routers in the Internet to discover the topology of the network which allows them to find optimal (in terms of some metric) rules for forwarding of packets (which are called routing tables) and to adapt themselves to the changing conditions such as outages of network links, building of new connections and so on. Most of these routers are costly dedicated devices running obscure firmware which is hard to configure and not open to any changes (on the other hand, their special hardware design allows them to keep up with lots of high-speed network interfaces, better than general-purpose computer does). Fortunately, most operating systems of the UNIX family allow an ordinary computer to act as a router and forward packets belonging to the other hosts, but only according to a statically configured table."
"Polipo is a small and fast caching web proxy (a web cache, an HTTP proxy, a proxy server). While Polipo was designed to be used by one person or a small group of people, there is nothing that prevents it from being used by a larger group.
Polipo has some features that are, as far as I know, unique among currently available proxies:
Polipo will use HTTP/1.1 pipelining if it believes that the remote server supports it, whether the incoming requests are pipelined or come in simultaneously on multiple connections (this is more than the simple usage of persistent connections, which is done by e.g. Squid);
Polipo will cache the initial segment of an instance if the download has been interrupted, and, if necessary, complete it later using Range requests;
Polipo will upgrade client requests to HTTP/1.1 even if they come in as HTTP/1.0, and up- or downgrade server replies to the client's capabilities (this may involve conversion to or from the HTTP/1.1 chunked encoding);
Polipo has complete support for IPv6 (except for scoped (link-local) addresses).
Polipo can optionally use a technique known as Poor Man's Multiplexing to reduce latency even further.
In short, Polipo uses a plethora of techniques to make web browsing (seem) faster."