Do-It-Yourself Caching: Squid 2.3 - page 9
Why Caching is Essential
One of the chief arguments against production use of any open-source solution is limited support. In truth, there are many companies willing to provide Squid support for a price: you'll find several enumerated in the Squid FAQ. There is also a wealth of free troubleshooting info in the Squid Mail Archive. Squid source is maintained by NLANR, funded by NSF. Most of you are familiar with the tradeoffs between open source and commercial support, so we won't belabor this point.
We spent less time installing Squid than we'd expected, but far more time tuning Squid than we'd planned. Had we started with a more robust hardware platform, we would not have run into as many problems--but running into these problems gave us a better feel for the effort needed to actually deploy this open source cache. Many great minds have contributed to Squid development; the version we tested had clearly benefited from improvements made over time. If you want to learn about caching, Squid is an excellent way to get started. But unless you have small network and are willing to commit hardware, time and effort, you'll get a more leverage by purchasing a commercial product for large-scale production network caching.