The most efficient solution to these networking problems is to use your existing network infrastructure to localize traffic patterns, enabling content requests to be fulfilled locally. A proxy cache operates by explicitly cooperating with the browser. Rather than directing HTTP requests to a target Web server, the browser directs them to the cache. A transparent cache is so named because it works by intercepting the network traffic transparently to the browser. In this mode, the cache short-circuits the retrieval process if the desired file is in the cache.
Transparent caches are especially useful to ISPs because they require no browser setup modification.
A server accelerator is a proxy cache that stands in for one or more specific Web servers rather than working on behalf of a group of browser users. National Science Foundation funds squid project, Squid has its presence in numerous ISP's and corporate around the globe. Based on the inputs from the Squid user community listed below are the benefits of Squid in Web caching. And most of the existing users of commercial products have switched to squid because of some or other problem with the commercial products Above that, the products which are having good price performance mix, vanish of fast because either they are not able to market the product or they were not able to support their customers. Customer pays for the support and not for the product Standard hardware, allows flexibility on the hardware investment.