Free web proxy

HTTP proxy to act as a web proxy throught HTTP protocol; HTTP requests from a web browser (the client) are passed to the proxy, which modifies the request header and passes the request on to the appropriate web server.
In this way, the web proxy can provide Internet connection sharing for web browsing on machines in a local network.
Machines on the local network pass their web requests to a web proxy running on one machine which has a connection to the Internet, allowing the machines to share that one connection.  If the
web proxy is smart enough, it can even handle SSL (https) web requests.

In general proxies act as a proxy server, also known as a tcp/ip port forwarder program. A proxy server is an intermediary between a tcp/ip client program and the corresponding tcp/ip server program.  Instead of connecting directly to the server, the client connects instead to the proxy, which then connects to the server.  The proxy reads tcp/ip socket data from the client and writes it to the server, and at the same time reads data from the server and writes it to the client.  In most cases, the proxy does not alter the data.  The proxy is
transparent (invisible) to the client and server programs, except that performance may be decreased slightly and they may have to be configured to use different tcp/ip port numbers and host names or IP addresses.  It's also possible to have a chain of 2 or more proxies between the client and server.

If 2 proxies are used, one on the client side and one on the server side, they can authenticate each other and encrypt all data passing between the client and server, thus establishing a secure "tunnel" between them.  This tunnel protects the data from being viewed or modified by any software or hardware in the tcp/ip path between the two proxies.  This is important for protecting usernames, passwords, and other confidential data.