No. 5: Open Solutions

Annual growth: 80.8%
Category: Financial data processing, Internet banking
Employees: 1,700
CEO: Louis Hernandez Jr.
Competitors: Fidelity National Financial, Fiserv

Founded in 1992, Open Solutions has tried for more than a decade to sell software to some of the most cautious I.T. customers in the world—midsize banks and other financial institutions.

Only in the last two years has the company gathered real steam, says CEO Louis Hernandez Jr. “This market is full of inertia,” he says. “Bankers are a conservative buying group.” Sales cycles in this industry, he notes, usually last at least two years.

Open Solutions developed its core banking application on Microsoft’s .NET programming framework. A key differentiator from competing products is that its code can run on multiple operating systems and hardware platforms, including Unix and Intel-based servers, and is optimized to run on Oracle databases.

The company now has 1,200 clients for its core-banking application. Hernandez, 39, expects to hire 450 employees in 2006, expanding the company’s head count by more than 25%.

“What I worry about,” Hernandez says, “is opportunity lost.”