We are planning to move some of our Linux services to a Windows platform. What is the equivalent solution on the Microsoft platform to setup a web cache for outgoing traffic?
Squid doesn't care what type of system is initiating web traffic, so you can just continue to use Squid, although there is a Windows port if you want to run Squid on Windows for some reason (http://squid.acmeconsulting.it/SquidNT26.html).
If you are looking to become a Microsoft shop, then Internet Security and Acceleration Server (more commonly known as ISA Server) will do the trick (http://www.microsoft.com/forefront/edgesecurity/isaserver/en/us/default.aspx)
If you want a working proxy for Windows out of the box: FreeProxy is very easy to install and configure. You only need to configure the service to get it up and running.
The basic features include proxying HTTP, SMTP, POP, FTP Proxy, TCP Tunneling, and SOCKS 4/4a/5. It works well with a wide range of programs. Besides browsers, it supports ICQ, MSN messenger etc. There is a comprehensive help which illustrates the setup of these clients.
In addition, FreeProxy can be authenticated to a internal user database or using a Windows domain. There is extensive reporting, control of resource permissions, URL filtering, IP address filtering, local port binding, demand dialing, calendar control, proxy chaining. It also includes a fully working Web server. It runs as a service on all Windows versions (server and desktop.)
FreeProxy is a free, but professional tool and qualified for volume usage. The newest version also includes SMTP and POP server functionality.
I've always used Squid for Windows. It's maintained seperately, and is avaliable here:
Sun's Sun Proxy server is free. Its pretty bulky, but it does AD intergration. Never used it beyond playing with it since we don't need a proxy, but that might be an option for you.
Squid will run nicely on Windows. We have been using it for over a year now as a web cache and web filter using free blacklists.
Be sure to run it as a service and to hide the output. (I am at home and dont have my notes with me, but will post some helpful hints here when I return to my office)