The U.S. economy runs on Wall Street, and more and more, Wall Street is turning to Linux to run some of its most complex server applications."The great thing about Linux is that you can use real TCO [total cost of ownership] as the selling point to get your organization to buy into something that also lets [you] do innovative things," said Evan Bauer, an independent software consultant and former CTO at Credit Suisse First Boston (CSFB).Bauer was one of a panel of financial IT execs at last week's LinuxWorld Expo who debated the pros and cons of Linux as a core platform in the financial services sector.\u00a0CSFB turned to Linux to run one of its busiest trading applications when its RISC-based Unix infrastructure became outdated. As a result of this infrastructure change, "the trading desk was able to make $20 million more in a year, Bauer said. "[CSFB] could take on more business because our trade flow was increased."Robert Lefkowitz, director in the Technology Architecture Group at Merrill Lynch, also praised the malleability of Linux, due to the availability of source code and the ability to work with open source tools and programmers to create a unique piece of code for a certain task."One of the strengths of free software is that it's not an either\/or proposition," Lefkowitz said. "It gives you the opportunity to take bits from here and there and make the 'borgish' thing that can satisfy [almost] all of your computing needs" for a specific task, he said.One panelist took a more skeptical view."At the end of the day ... Linux will have to stand on its own as a technology," Ryan said, adding that choosing open source for the sake of open source is not wise.Open source operating systems, he added, "have a tremendous opportunity to succeed, but the Achilles heel for those products will be if they are oversold on the merits of their openness and not on the merits as an operating system."