Web proxy software forwards HTTP requests without modifying traffic in any way. They can be configured as a transparent proxy with no client-side configuration required. They can also be used as a reverse proxy front-end to websites; here the cache serves an unlimited number of clients for one or some web servers.
To provide an insight into the quality of software available for Linux, I feature below 5 excellent open source web proxy tools. Some of the them are full-featured; a couple of them have very modest resource needs.