I'm looking for the best firewall operating system (preferably for free) in existence.
It must be secure, it must be reliable and stable, and it must be as close to "industry standard" as possible.
Also, it must *not* be a piece of software which needs to be installed onto an existing operating system, the firewall must be an operating system itself.
Can anyone recommend any of the above? Are there any "famous" ones in existence, or ones which thousands of people use and rely on?
Thanks in advance!