NEW YORK -- Wall Street firms increasingly are buying into Linux, but some still need convincing that open source licensing and support models won't make using the technology more trouble than it's worth.

Linux providers, speaking this week at the Securities Industry and Financial Markets Association (SIFMA) conference in New York City, stated their cases that Wall Street firms have nothing to fear about diving into open source. Red Hat and Novell argued that's especially true now that specialized Real Time Linux has been developed that meets strict low-latency and messaging requirements of brokerages and trading firms.

"There's a strong business case for Linux as an alternative to Microsoft or Unix derivatives," said Roger Levy, senior vice president and general manager of open platform solutions at Novell, which late last year released what it calls SUSE Enterprise Real Time 10 specifically for use in organizations that have millions or billions of dollars at stake based on how quickly they can complete trades.

In addition, Levy said Novell has released the alpha version of SUSE Studio toolkit for "mass customization" of Linux, adding this is "something a proprietary systems vendor would never do."

Click to see: Chart showing Linux becoming more prevalent at Walll Street firms.

Red Hat, which last month celebrated news that the New York Stock Exchange (NYSE) and its international subsidiaries were adopting Red Hat Enterprise Linux and dumping Sun's Solaris, also has a Real-Time Linux version. Its Red Hat Enterprise MRG uses the Advanced Message Queuing Protocol developed by financial institutions JP Morgan Chase Bank and Credit Suisse with contributions from Cisco, Red Hat, Novell and other high-tech firms.

"This is about not just being fast but guaranteed-to-happen within a certain window," said Michael Tiemann, vice president of open source affairs at Red Hat.

But even as the Wall Street crowd increasingly puts its money on Linux — market watcher Tabb Group estimates that Linux adoption among the 14 biggest investment firms this year will reach more than 72% of the installed operating server base vs. 60% in 2006 — it's clear concerns linger about the licensing model. That model requires users return changes to the open source community under certain circumstances, a touchy subject for companies that are battling to accelerate their business processes.