The adage 'you get what you pay for' doesn't necessarily apply to the freeware and open source software available for download at no cost.

For many corporate IT managers, free tools provide much-needed technology in a pinch and augment existing investments in commercial products. While the nonexistent price tag initially draws people to freeware, it's the versatility the downloadable tools provide that keeps users coming back, proponents say.

Kerry Miller, network engineer at First Victoria National Bank in Victoria, Texas, says his organization recently started using a program called Argus to monitor servers and routers in the bank's network. Miller says the software application is similar to Ipswitch's WhatsUpGold commercial software, but it's free. He uses Argus in conjunction with Multi Router Traffic Grapher - a freeware staple for many IT managers - to monitor connections and bandwidth.

"Argus is something we stumbled across, and it turned out to be much better than the commercial products we looked at" for monitoring about 30 devices, Miller says. "It didn't require as much customization for us to get it working."

Miller also uses Snort intrusion-detection software and ACID , a tool for analyzing Snort event data. For Miller, ACID makes the data Snort collects more accessible to non-expert IT staff.

"If you have some networking experience, these tools definitely are easier to use, but adding the Web-based front end makes it simple to run reports on the Snort data collected," Miller says.

In some cases, freeware solves an unusual problem for users who couldn't find the same features in a commercial offering. "There is a lot of good technology out there that wouldn't draw a big enough commercial market," says Mark Douglas, vice president of engineering and operations at online dating company eHarmony.com in Pasadena, Calif. "So I can get technology that would otherwise not be available to me."

Douglas recently started using FileZilla, an FTP client program that helps him move files between data centers without adding a line item to his budget. Douglas uses many open source technologies such as Tomcat, MySQL and Apache .

"The plus with open source and freeware is that it's not just what you can write yourself to solve a problem, it's what all your peers are creating and sharing to solve universal problems," Douglas says.

Douglas uses search engines such as Google when he needs to find a specific tool. He also stays on top of what's available through RSS feeds from download sites such as freshmeat.net and SourceForge.net .