I hope you're sitting comfortably.

My name is Mads Torgersen,

and known in America as Mads Torgersen.

I work on C# for Microsoft.

I'm getting old, so I always carry a t-shirt

with the name of the program and language

I'm working on in case I forget.

And I'm here to talk about C#,

and why it may be worth thinking about,

even if you haven't so far.

So let's get the embarrassing details over with.

How many people are already familiar with C#?

(laughs)

That's a lot.

How many are not?

Wow.

So I will completely fail,

introducing somebody to C# at this talk.

Good to know.

We can maybe breeze over some details I had planned on,

and get into some I hadn't.

So, even so,

they say that the reason why

they make those SUV commercials,

is not to make people buy them.

It's to make the people who already bought them feel good

about the fact that they did.

So maybe I can achieve that.

So, I have been asked to remind you to evaluate the talk.

It's good for me, because then if I do something

in an unsatisfactory way, I can do it better

next time, maybe.

And it's good for the GoTo folks,

because then they can decide

whether to invite me again some other time.

So this is in the feel-good department.

Stack Overflow have a survey every year

of their developers,

and they ask them various questions,

and, of course, it's skewed,

and unscientific in all kinds of ways.

First of all, you have to be on

Stack Overflow to participate,

but I like the numbers, so I'm gonna use them anyway.

So if we look here,

C# is a very widely used language.

It's number four here, of the three above,

one of them is not a programming language.

So I'm not talking about JavaScript.

I'm talking about SQL.

So C# is definitely a language

that's in broad usage already.

It's one of the, sort of, main mainstream languages,

if you will.

And they also ask people

whether they would like to continue

using the language they're using,

and they use that to rate the most loved technologies.

And it's interesting to see that C# is on this list as well.

So people actually love C#, to some degree.

There are some languages that they love more,

but if you notice, many of them are languages

with smaller audiences, sort of very dedicated

audiences that are maybe more part of a cult

or something.

But it's only a few here at the bottom

that are actually in both lists,

that are both highly used and highly loved.

So it's nice to be one of the three technologies

on that list, two of which are programming languages,

and yay for Python also for being on there.

Right so, we and Python, we must be doing something right.

And we constantly try to think about,

what is it that we're probably doing right,

that we have still fairly enjoyed

programming language after all these years.

So it seems to be not the fact

that everybody uses to C# just because they have to,

because people did 10 years ago at their company,

and they have all this legacy code.

There seems to be some kind of energy around,

and we wanna try to keep that going.

And we have some ideas about why that may be,

and that's sort of what is driving

our language evolution, if you will.

So we'll get back to that a little bit later.

But I think one core thing to point out here is that

we are very eager to evolve C#.

Like if you look at the language evolution

scale from a little to a lot,

we are kind of over there.

As mainstream languages go, we kind of tend

to be pretty aggressive about keeping the language fresh,

and keeping it modern.

And as the programming language

state of the art evolves, so do we.

And sometimes we are the movers,

and sometimes we are the followers,

but we try to keep the language

a good choice for programmers in modern day.

Not just something you have to do

because somebody made that choice

in a previous decade.

So that's kind of our philosophy around it.

I also wanna point out F#, because it's our little sister

language, and it's very popular,

because it's also very small.

And there's a talk next door

about it at the same time.

So I'm sorry that those are scheduled at the same time.

But F# is a very much more functional language,

and we have a lot of benefit

from the collaboration with F#,

and the kind of inspiration that it gives us

in the C# language design as well.

So I wanted to call that out.

So how many of you use C#

on something other than Windows?

Okay, thank you.

It looked like none for a second there,

now it's more like two percent.

Good.

That's a lot.

So most people use C# on Windows,

and that's because that pretty much used to be

where you could use C#.

And we kind of are changing our tune on that.

So part of the reason I wanted to frame

the talk in this way was that we're really pushing.

It's sort of increasingly been the case,

that you can use C# elsewhere,

but we're pushing to make that an option, right.

We're sort of in this weird situation,

where C# has been a massive,

main programming language in Windows,

but at the same time,

we are like complete newcomers

to some other platforms.

At least mostly so.

And so it's this interesting situation,

where now that it's actually becoming an option

on all the platforms,

we're at the same time very entrenched,

and also very new and kind of the fledgling

language on some of those platforms.

We're eager to help that adoption

on those other platforms.

One other thing that is changing how and where

you can use C# is the fact that we've evolved

our language technology.

So the compiler and IDE technologies

that underlies the implementation

of the language quite a bit,

what we call Project Roslyn,

and that's enabling some, I think,

quite unique scenarios about

how you can program in C#.

I'm gonna show a little bit of that,

because I think it's nerdy and cool,

and maybe it's also useful to you.

One of the consequences of that is that,

that work on sort of the language core,

and ripping it out of the, sort of,

Windows and Visual Studios specifics,

means that it's become very easy,

as these things go,

to implement C# and others IDEs.

So you can essentially use C# in your favorite IDE,

and we'll talk a little bit about that as well,

or your favorite editor.

And of course, one of the big changes is we've moved

from being a completely proprietary technology,

to being completely open source.

So everyone can contribute to C#,

and a lot of people do.

And we're getting a conversation

with the community that's vastly different now.

It's more of a collaboration project,

as opposed to, "Microsoft says..."

And that's very exciting.

It means that, rather than coming out

every three years or whatever, and saying,

"Ta-da, this is what we worked on, hope you like it."

We are now in a very open dialogue

everyday with the community about our direction.

We get feedback all the time.

Like probably, tens of you will come to me after,

and say why we should be doing something different,

or proposing things.

And that happens online, and on GitHub,

and elsewhere as well.

So we have a much better,

we have much better quality

on our design work as a result of it, I think.

Okay, so that's a couple of good things.

Let's start with some of those other places

that C# are.

So how many people here have used Xamarin?

So a few there.

Have you all, you must all have used Xamarin

on non Windows platforms, right?

That's probably the reason why you do.

So Xamarin, how many people are aware what Xamarin is?

Okay, about half.

Xamarin, it used to be a separate company.

We acquired them six months ago.

It's a technology for using C#

to target, to make native apps for Android and iOS.

So it's technology that's very much based on

letting you use the same language,

and the same source code, for the most part,

to write apps for multiple different

mobile platforms, right?

So it works on iOS, it works on Android.

It actually targets Mac as well,

and by the way, Windows too, if you want to.

And it creates high-quality native UIs.

It's a number of big apps that are using this technology,

because it saves the effort of separate implementations

on those platforms.

It also lets you use the language

that you can use on the back end as well,

which, yes you can with Java,

but it's not quite there yet with Swift or Objective-C.

And so, it's sort of economy of scale,

and it's also just a very good language

for implementing apps.

It's based on the Mono project.

How many people know about the Mono project?

Okay, about half.

That is an open source implementation

done by people outside of Microsoft many years ago,

and maintained ever since to target C#

to other platforms and Windows.

While we at Microsoft were sort of tunnel-vision

on Windows for many, many years,

these people saw the cross platform potential

of C# much before we did and implemented

this great cross platform.

Cross platform implementation.

So Xamarin is based on that,

and a lot of the apps that you see

in the iOS or Android are stores

that are actually based on C#.

Either because of Xamarin,

or because of Unity,

which is probably the industry leading game engine.

So if you're up there on the back rows

playing a game instead of listening,

chances are, it's written in Unity.

Right, so even your hands are engaged i