freeware firewalls

A firewall is a computer, sometimes called an appliance, which sits between two or more networks and performs nothing (or very little) other than firewall functions.

So your question cannot be answered without considerable information about what you want the firewall to do.

I am not aware of any free firewalls because a hardware platform is always required. You also need to have considerable networking experience to correctly configure a firewall.

If you are asking which is the best free firewall software to install on your Windows computer then all such software is crap and you should use the built in Windows firewall. Anti-virus software is a good idea but forget about firewall software.

Also find out about backup, if you haven't already, and why it's even more important than anti-virus.

OpenBSD PF is extremely well revered.

Very interesting. I just read the Core Force user guide.

No doubt the core firewall code is of very high quality but I can't help thinking that pop up messages like "an application is trying to access a file.. do you want to create a rule?" and "Your computer is trying to connect to a remote computer..." will be just as useless to the average Windows user as those produced by the better marketed and not very good personal firewalls. It's my assumption that the OP was asking about firewall software for Windows.

That's my assumption too.

I'm just being a pain in the ass about a poorly constrained question that--even if well constrained--is bound to draw the usual litany of responses about personal firewall software that we usually see, all the while no one giving a good authoritative recommendation based on head to head technical testing of products.

:-)

You wouldn't expect to see other than officious sarcasm in a group haunted by the ghost of Duane Arnold, regardless of whatever nymshit handle he now hides behind. Maybe I'll have to peek in the virus newsgroup to see if he's still giving phony advice over there too.

Untangle

has as one of its many components a firewall. Untangle is an open source project which runs on most pc's as a dedicated unit to function as a web filter, firewall, anti-spam, intrusion prevention, and more functions. It loads itself and is rather simple to use. Only drawback I have seen is that it does not run or load on some hardware. gr

Yep. It looked good to me too, but wouldn't run on my rig. Clark Connect did, and it's great!

I agree Packet Filter (PF) on OpenBSD/NetBSD/FreeBSD is the best choice. On NetBSD or FreeBSD you must recompile the kernel to enable it.

PF on OpenBSD is so much more than just a firewall, you have many more capabilities.

The Book of PF: A No-Nonsense Guide to the OpenBSD Firewall by Peter N.M. Hansteen, Bob Beck ISBN-13: 9781593271657