Apparently they got tired of the Windows problems. -Greg Smith (GregMS)

http://blogs.computerworld.com/14876/london_stock_exchange_dumps_windows_for... By: Steven J. Vaughan-Nichols

When it comes to business computer systems, nothing is more mission-critical than the massive trading software systems that underlie stock markets. A failure of an hour here can mean billions of dollars of lost trades. The LSE (London Stock Exchange) learned that the hard way when their .NET/Windows Server 2003 trading platform diedhttp://blogs.computerworld.com/london_stock_exchange_suffers_net_crashlike a dog early last September. The new LSE management is not going make that mistake again. This October, the LSE purchased MillenniumIThttp://www.ibspublishing.com/index.cfm?section=news&action=view&id=13440and will be switching its stock exchange programs to the company's Linux-based Millennium Exchange softwarehttp://www.millenniumit.com/capital_market_solutions/index.php#.

I saw this move coming. While the LSE never officially announced that its Windows and .NET stock trade software TradElect was the root of its September failure and perpetually slow performance, it was an open secret in the City -- London's equivalent to America's Wall Street -- that that was the case. Indeed, it was this technology flop that lead to the LSE CEO Clara Furse leaving the Exchangehttp://blogs.computerworld.com/london_stock_exchange_to_abandon_failed_windows_platformin July. The new CEO, Xavier Rolet, immediately decided to get rid of TradElect and started shopping for other platforms.

Friends of mine in the City tell me that the LSE immediately started considering a Linux-based solution. It doesn't take a genius to see why. The world's fastest stock exchanges, like New York's International Security Exchange, run on Linuxhttp://blogs.computerworld.com/14637/linux_powers_worlds_fastest_stock_exchange. In a world of high-frequency tradinghttp://www.bloomberg.com/apps/news?pid=20601109&sid=aBBFQ6thBuiYwhere a millisecond really can mean the difference between profit and loss, stock exchanges can't afford to be slow, never mind actually going off-line.

The platform itself is built primarily on Linux, but Solaris and Cisco networking also play important roles. The back-end database engine is based on Oracle. The LSE expects to see transaction speeds drop from a claimed best speed of 2.7 milliseconds -- which was rarely, if ever, seen under TradElect -- to the Linux solution's claimed 0.4 millisecond speed.

It wasn't just raw speed though that brought the LSE to Linux. Linux is cheaperhttp://www.computerworlduk.com/community/blogs/index.cfm?entryid=2568&blogid=14, a lot cheaper, for high-end servers.

According to an IBSJ report, David Lesterhttp://www.ibspublishing.com/index.cfm?section=news&action=view&id=13440, director of information and technology at LSE, said that compared to the annual bill of $65 million for TradElect, MillenniumIT was a bargain at a purchase price of $30 million. The LSE predicts that moving to Linux will give the company an annual cost savings of at least £10 million ($14.7 million) from 2011-12. In addition, "The new technology is a lot lighter, nimbler and easier to install" and will also enable faster releases.

The LSE hopes to close the deal this month. The transition from TradElect to the MillenniumIT is expected to take up to 18 months. Lester hopes to get it completed faster than that.

In the end, the LSE and its traders will profit from this move. As Steve George, director of corporate services at Canonicalhttp://www.canonical.com/(the company behind Ubuntu http://www.ubuntu.com/) told me when we talked about the deal. "When performance and stability matters, as they do in business, Linux is the positive choice. This move will be good both for the LSE and its customers and to the wider family of Linux."