The LSE is far from the only one stock exchange to switch to Linux. More and more stock exchanges are realizing that when you really need speed, security, and stability, Linux is the operating system you need.
It's not the only stock exchange that's found that Linux worked better. The Johannesburg Stock Exchange in South Africa is moving to Millennium Exchange. The LSE's parent company is in the process of acquiring the Toronto stock exchange so it will soon be using Linux as well.
So why is the biggest of big business switching to Linux from Windows and Unix? It's the three "Ss": speed, security, and stability.
Day trading is so 20th century. Today's sharp traders make their cash by running programs that trade milliseconds ahead of the other guy in High Frequency Trading. To do that you need really fast stock exchanges, which is where Linux comes in.
As a Deutsche Borse representative told me these days, "Speed, or 'low-latency,' is everything for exchanges. A fraction of a second can mean mega gains or losses to investors. Transactions that once took minutes and seconds to complete are now processed in thousandths and millionths of a second, with the fastest trading engines reaping the biggest benefits."
They also have to be secure. When you're looking at a million plus transactions per second, which is what both the LSE and Deutsche Borse claims their platforms can do, you don't want anyone messing with the till for even a micro-second.
So it was that September 8th 2008 was a black letter day for both the LSE and Windows. But, as it turned out, it would be a red letter day for Linux as Windows' very public failure impelled the LSE, and other exchanges, to finally move to Linux.