Although I have written a formal opinion for The Register that Windows has more yesterdays than tommorrows these things are slow.I also say this about Java, so one must be careful about where to jump and the right time scale to exit.Many argue with me about Java, because they see the truly vast amount of Java employment and again this will take decades to fade.But...It's bog standard supply and demand. The supply of Java skills is increasing rapidly, now being the dominant language in undergrad education and many have done it as teenagers.That means supply/demand is getting weaker for those with Java skills.Also of course, skilled labour has huge lags in it, last month I was asked to help someone with a tech I had not touched in ten years, but still could hack my way through.So you're competing with the area under the curve and nowadays that's literally tens of millions with Java.It is even affecting the .NET market which is led by C# which is close enough to Java that you can move across without too much pain.Note the jump in outrun's graph, I don't know what caused it, but the general evolution is more of less the opposite of equities, ie drifts down and jumps up. This is because very few events will cause C# (or Java or F#, or Matlab) skills to jump down, but a technology suddenly becoming fasionable or useful can be quite quick. MS will at some point do something that boosts .NET, possibly IoT, maybe somehow getting a good chunk of the mobile market, or something. It will happen and it will be good for .NETters and of course it will fade because all skills do, the vartiable is rate.