Performance-Wise, C# Trumps Java

Working on C# OSS means stealing licenses from your employer, buying an MSDN subscription on your own dime, or evangelizing enough to get an MVP award so you get all the tooling for free. The free Express editions of the tools have built in limitations that don't make them viable for building Big Data projects. Other options exist, but pale in comparison to Visual Studio so they don't get much use.

As for mono, the uptick for the OSS stuff just isn't there and even Xamarin is leaning on commercial offerings to become a viable business. Maybe as they get more successful they can sponsor some C# server projects, but that may be a ways off.

This is all unfortunate, as C# really is a great language.

Tech people who have to handle that kind of data and that kind of volume generally don't want to pay a Microsoft tax. In theory there are a lot of other alternatives. However all of the popular ones are Unix based and either are native to, or ported to, Linux.

There are exceptions. For example eBay decided for political reasons to go the Windows/Java route some years ago. (And reportedly paid a factor of 2 cost differential for it.) But Google, Facebook, Amazon, etc see no reason to be dependent upon Microsoft, or to pay that level of tax to a potential competitor.

Furthermore, I doubt straight-line execution performance is really the biggest concern when choosing a language to use for a task like this. You probably want to prioritize being able to find people who know the language - or, if you're using existing staff, you pick something they either know or can learn easily. C#'s not hard to learn but the odds are better that your typical CS graduate knows Java. In particular, if you want high performance, high performance C# isn't particularly easy to write - you'll have to know the language well, just like in any other environment.

Can you even set up a bunch of windows server nodes without running into a licensing headache?

TL;DR Don't look at data, look at the principles. Ignore reality, think about how the world should be. I think as an industry we can't aim lower than this quote:

"In fact, C# is a better fit than Java for high-performance requirements. I'm not referring to VM stats that change every year. C# has been designed from the ground up with efficiency in mind."

And a side note:

"Both C# and Java have generational mark and sweep collectors."

No Java hasn't.

However, I clicked on this article expecting to see some performance benchmarks to justify the title. Rather, I see some theory about why it MIGHT be faster and also some opinions about what features might make a developer more efficient in C# than Java. I worry that any actual benchmarks would not validate the title. Certainly the web application benchmarks I've seen elsewhere do not align with the title.

Ultimately, it seems to partially conflate performance with developer efficiency. Developer efficiency I am willing to concede: C# may be more developer friendly as a language, putting platform aside.

The first version of C# was a 'meh' - Microsoft's Java(I already know Java; why bother?). C# got interesting(and a better Java IMO), but it took time. C# didn't have package management concepts till late(nuget is still in its infancy), and small to non-existent open source ecosystem. For a long time, it didn't run on anything else but Windows. Hobbyist who weren't willing to buy Windows(doesn't matter much if it comes with your system) and VS licences(express edition came late and explicitly disallows commercial use) didn't try C#.

I've had legal copies of VS for years through this.

To the comparison with JAVA - C# is not really cross-platform. I wish for C# on the JVM. Hope that becomes true someday.

Windows has many problems but one of the worst is poor file system performance. On Windows you waste a lot of time moving large files around when you would hardly notice these times on Linux.

The problem is that there is no community behind it. The vast majority of C# programmers are do-the-bare-minimum-contractors who hang up their keyboard at the end of the day and go home to their Top Chef and NFL on TV. Those people don't contribute to anything in any community, let alone the open source community.

There are a lot of ways to be able to do C# for free, both as in libre and as in gratis. Mono has about as big of an OSS community behind it as you will find in C#, and it even has support from Microsoft. The language itself is an EMCA standard, and much of the CLR VM and runtime library are, too. The parts that aren't OSS in the library have very reasonable alternatives, in fact, even if OSS wasn't a concern for you, those alternatives are so good you should probably be using them anyway.

And it's in almost every package repository out there, certainly all of the ones I've tried. I personally think setup is a sight easier than Java. I've personally found it a little easier to get setup with Mono that with Java; there is some fragmentation in Java that, while not insurmountable, is still a small annoyance.

Yes, you're not going to get a great IDE for it yet. MonoDevelop is buggy in weird ways. You could cheat and run VS Express in WINE, but I have a feeling some people are going to have a problem with that for no good reason other than to have a reason to complain.

I'd say, if you're the type of developer that is capable of putting together her entire toolchain from the ground up, C# is one of the best languages out there and it's a shame more people don't consider it. If you need hand-holding, then yes, it's really hard to do C# well on anything other than Windows. It's getting better, and will continue to grow, so don't discount it completely.

A: MS Tax to run it.