Proxy for a home network
What would be a good proxy for a home network?
- I'd like to install the software proxy on 1 machine and to share it across my LAN
- how can I configure my Linux Ubuntu machines to use the proxy just for specific domains? (e.g. www.gravatar.com)
Firstly, How many users are we talking about?
As suggested by Arcath, Squid is the de factor standard these days for open source caching proxies. Various add-on packages allow content filtering and several programs have been make to do fancy reporting against Squid's logs.
A good lightweight caching proxy is Polipo. It's not the fanciest thing in the world, but it's small, fast, and should work well enough for a handful of users.
Concerning your second question, Squid's ACL functions can be used for caching only certain sites. I'm not sure why you'd go through the trouble of setting up a proxy but not want the clients to take full advantage of it, though.
Squid is a rather good proxy, the wikipedia article might be a good resource http://en.wikipedia.org/wiki/Squid_%28software%29
If you want a proxy for apt updates, look at apt-cacher-ng. I used that on my cluster at work.
The other answers are for general-purpose HTTP proxies that don't specifically know about Packages.gz, Releases, and .deb files. apt-cacher-ng uses that for cache staleness decisions.