Chris Shank and Mitchell Perilstein, the owners of Ace Technology Group, save their Philadelphia-area small business clients money and make their computers more reliable by installing Linux and other open source programs.

But they don't sell Linux or even tell clients they're using it unless they ask, which most of them don't since they are mainly interested in having their systems run as smoothly as possible for the lowest cost, and don't care what software Ace installs as long as it helps them achieve those two goals.

Ace is one of a growing number of information technology service companies that use Linux and open source software to win computer installation and maintenance contracts from cash-conscious small business managers.

"Our main strategy is to reduce their costs by preventing problems proactively," says Perilstein. Ace accomplishes this typically by remotely monitoring clients' computers so that they can "catch some problems early," including "some we can fix before the customer notices [them]."

Shank says that once they're in a client's door, the way Ace earns long term trust is by providing "responsive help remotely. We don't take hours to answer a service call."

The lack of licensing fees associated with most open source software helps keep initial costs low, but the real savings come using two programs -- OpenSSH and rsync -- which make it easier to administer Linux remotely while also managing secure, remote data backups over the Internet. While there are third-party software tools available that allow remote administration of Windows computers, this capability is inherent in Linux.

These two tools, used together, virtually eliminate the need for onsite service calls to solve software-related problems.

With business owners looking for cost-effective solutions, not only service companies such as Ace Technology Group, but also product vendors including New York-based Symbio Technologies are creating an expanding array of plug-and-play Linux solutions for small business.

Symbio Technologies sells servers pre-loaded with Linux and low-cost diskless desktop units that run programs from the server instead of acting as standalone computers, in effect creating a plug-and-play Linux system for small businesses.

A Symbio desktop unit costs as little as $200, plus monitor, and has only a minimal operating system that is automatically loaded from the server each time it is turned on. Symbio's servers start at $3000, and even the smallest ones can power between five and 10 workstations, says Symbio CEO Gideon Romm, "depending on the number of applications they're running and how resource-hungry [those applications] are.