IBM has unveiled a line of mainframe computers to expand the market for big iron machines beyond traditional customers like trading firms and research houses. Big Blue is continuing to invest heavily in mainframes, like the LinuxOne line introduced Monday, even as such systems are widely seen as relics of the early NASA programs and 1960s corporate data centers.

But in an age of almost daily hacks against the government and private companies, IBM sees mainframes as more relevant than ever. The company argues they are inherently more secure than distributed computing systems, which rope together hundreds or even thousands of smaller, cheaper servers -- manufactured by Dell, Hewlett-Packard, Lenovo and others -- and are commonly used in cloud computing.

IBM said the new mainframes’ concentrated computing horsepower, for example, gives them the ability to spot fraud on, say, a financial network, even as it is happening. Mainframes, Big Blue further argues, are better at handling the demands of the so-called Internet of Things -- a wired economy in which everything from toasters to autos are going online, not to mention huge volumes of data requests from smartphones and other mobile devices.

IBM’s new mainframe line features two models. The LinuxOne Emperor, the company claims, has the fastest processor in the industry and is able to handle more containers -- self-contained systems that live within the larger server -- than any other Linux machine. The LinuxOne Rockhopper is aimed at customers seeking a smaller package. This is the first time the company has offered a Linux-only mainframe. Linux is open source software, meaning any developer can contribute to its feature set. That saves IBM money on internal development costs and gives customers access to a broader set of applications. IBM last year launched an enterprise app store that is akin to an iTunes store for business applications.

IBM is pitching the new machines at investment banks, pharmaceutical researchers, academic institutions and other commercial environments for which processing speed and data protection are key. HR and payroll services giant ADP has been using Linux on IBM’s z mainframe systems. “Linux on z Systems gives us the ability to manage large amounts of data and transactions with speed and security while ensuring our system is always available even when demand spikes,” said Greg Levine, senior VP for infrastructure and operations at ADP.

IBM needs its big bet on Linux to pay off. It has struggled to grow sales as business computing moves increasingly to the cloud. The company’s overall hardware sales fell 32 percent year-over-year in the most recent quarter, though mainframe sales provided a bright spot -- up 9 percent.

The key, according to IDC analyst Al Gillen, will be whether IBM can get in front of new customers and convince them switching to a Linux mainframe is more secure and efficient. Providing an all-Linux offering supported by a worldwide developer community is what Gillen considers the best way for the company to expand the mainframe’s appeal. “Without Linux, IBM doesn’t have a story that resonates,” Gillen said.

IBM’s own research shows Linux installations on mainframes rose at a compounded rate of 45 percent annually in the past decade, and a quarter of all installed mainframe capacity is now on Linux. “The new LinuxOne systems are designed to capitalize on and accelerate those trends,” said Charles King, principal analyst at Pund-It.

To bring new developers into the fold, IBM also announced an open source community push. The company will contribute open source mainframe code, kick-starting the “Open Mainframe Project,” a collaborative effort created by the Linux Foundation to organize and encourage mainframe Linux development. IBM is also providing free access to the LinuxOne developer cloud, which will allow new developers to try out a virtual LinuxOne mainframe.

Also, IBM is introducing new financing models so businesses can pay for what they use and scale when needed, so if a company wants to use 100 processor cores for a six-month project and scale back when it’s over, they can. “If IBM can demonstrate a lower cost, they might have a value proposition,” said Gillett.