Need Free Commercial Firewall Software

Please specify what is meant by commercial because the obvious choice for most users would be Zone Alarm or Comodo. But if it is for business, then I'm afraid that I have yet to come across a firewall that they are willing to give free to a business as most have a subscription to a public line, where users buy bandwidth and the connection in a whole is channelled through a huge firewall. If it is a small business you may get away with installing Zone Alarm on all your computers individually or on your network server. I can give a more accurate suggestion if I knew more about the number of computers and the size of businessyou are controlling.

This may not be of any help but I wouldn't trust anything that was free.
But I could be wrong, I just have to wonder how do the developers get paid.

Matt.I like your caution.But I'm using PC Tools Firewall Pro,in Vista at the moment,as their "own" Firewall isn't good with it's default settings,and to get into the nitty-gritty,you need a lot of patience,or a degree in setting firewalls correctly (thank you Redmond).
In answer to your question,I guess a lot of third-party stuff is done by "free-lancers",who must work on other things,whilst "tweaking" a particular product.
Advertising,is probably the main answer.PC Tools,also "sell" Spyware Doctor.So I guess offering a good free firewall is not that much hastle for that company,but I take your point about developers being paid.

I should'ove mentioned this sooner, but I work for a NON-PROFIT ORGANIZATION that has no money for technology expenses, but next year we might have some extra cash for some "commercial grade" software.

Check if your router has a built-in firewall. Also, there indeed are a number of "free" enterprise-class firewalls out there, one of which I recommend is Smoothwall. Just set it up on an old PC and it'll take care of your entire network. It's pretty easy to set up and maintain even for Windows users, and has some good features for security-minded types too.