Fault tolerance and continuous availability are virtually synonymous with the name Stratus Technologies. That statement is as true today as it was in 1980, when the company, then known as Stratus Computer, launched with a focus on fault-tolerant computing for enterprises.

But the company has undergone significant change over the years. In a corporate nutshell, Stratus went public, got acquired and then privatised in a leveraged buyout. Today, it remains a privately held, partially employee-owned company. Stakeholders are Intel Capital, Investcorp, MidOcean Partners and NEC, which also inked a 10-year joint development agreement with Stratus last November.

There is a twist, though. Stratus has had debt in the public bond market, and has been legally obligated to release financials. Although its fiscal '06 data is not yet available, annual revenue growth has been creeping up year after year, reaching $272 million in fiscal '05, for the year ended Feb. 27, 2005. NW200 companies with similar revenue ranked at about the midway point. It has 650 employees globally, with about 255 in engineering

Key to Stratus' revenue picture are sales of the company's ftServer servers. The ftServer line resulted from Stratus' five-year transition from a vendor with proprietary hardware and software to one with open, Intel Xeon-based servers. For example, Xeon-based ftServer W Series servers operate with Windows, and the T Series servers support Red Hat Enterprise Linux. Stratus still offers its proprietary operating system in its ftServer V Series and Continuum systems.

At the Philadelphia Stock Exchange, V Series servers provide the fault tolerance and continuous availability required for the mission-critical options business, says Bill Morgan, CIO. "Stratus is the only vendor that offers a true fault-tolerant platform. Its implementation of fault tolerance is well done, efficient and, most importantly, stable," he adds.

In a November 2005 technology report, Butler Group analyst John Holden gave the Stratus servers a thumbs-up, saying the ftServers offer a good and relatively affordable option for enterprises needing to provide bullet-proof service levels.

Since moving to an Intel-based architecture, Stratus has doubled its user base to 5,000 customers, says CEO Dave Laurello, and it has penetration into new verticals such as healthcare and pharmaceuticals. He considers Stratus' transition complete, with the December 2005 Linux rollout, and says he is driving the company to be more of a solutions provider. Disaster recovery and application availability are new focus areas, he adds.

For the Philadelphia exchange, which has been working with Stratus for 17 years, the company has risen to any challenge, Morgan says. "The engineers know us well, and we know them. Stratus has always been a vendor that understands its niche."