[jen20]

We have been selling a relatively complex product built using C# for many years now. It is perhaps unusual in that it was built on Linux for Mono primarily, and then ported to .NET on Windows subsequently.

What we have seen over the years is:

1. Deploying on Windows became less popular, partly because it was much harder to manage at scale than Linux, and partly because of the price of licensing.

2. Mono was seen as a toy, and is often considered a critical risk by purchasers. This was even true after Microsoft bought Xamarin, and thus de-facto control of the project, and despite the fact that it was far easier to patch bugs in the open source runtime than in the closed-source .NET Framework (and we ran into several in each).

C# (and even more so F#) is a great language, but was hamstrung early on by Microsoft's approach to competition - I think had this been different early on, the world would look very different with respect to popularity for critical infrastructure vs the JVM. Whether it's late enough to salvage something for a large number of non-traditional-MS is debatable - it will be interesting to see how it plays out over the next few years.