"The new technology platform has been developed using the Microsoft .NET Framework, with support from Microsoft and Accenture, and marks the final phase of the Exchange's four-year Technology Road Map project. "[1]

I was also told that there were Microsoft engineers on site doing training and review through the project. Either way, my point is that building a trading platform is extremely difficult even with top talent and enormous investment.

[1] http://www.onwindows.com/Articles/LSE-TradElect-system-goes-...