[Edison’s direct current electricity system will be turned off after 125 years](http://cityroom.blogs.nytimes.com/2007/11/14/off-goes-the-power-current-started-by-thomas-edison/).
The Tesla v Edison fight is one of the great ones of all time. It’s also a good example of even apparently substantial ‘lock in’ can be overcome if one product is clearly superior. I’m looking at you, Microsoft!