What makes it the better choice in this situation? C# can't run in browsers whereas Office 365 can.

You mean JavaScript not Office 365 right? They are working on compiling C# to Web Assembly FYI.

IE11 will never support wasm, so I suspect wasm isn't their first choice eh

This is a good point. MS has agreed to support IE11 until 2025. I'm not sure if that means they have an internal mandate that Office 365 must work with IE11, but I wouldn't be surprised. Those poor poor MS developers.

I wouldn't call them "poor" in this case. WASM is super cool and has a hopeful future, but productionizing wasm apps is currently still quite difficult in practice - it's still missing a lot of relevant tooling (debugging is hard)

Well, blazor exists now, so that's not totally true.

They are actually using Typescript, and this will lead to less friction wrt hiring devs, supporting all those platforms and integrating web components. Still I would have hoped that MS would be a little more forward thinking, and put some of their MSR tech in good use, to encourage the use of better languages. Just like how Facebook is pushing ReasonML.

I think that the C# focus of .NET is a major mistake holding the platform back, especially when we have languages like F#, Scala, Swift, ReasonML and Rust these days.

How do you know they're doing that? Not that it doesn't make total sense to use TypeScript from any angle I can imagine.

> I think that the C# focus of .NET is a major mistake holding the platform back, especially when we have languages like F#, Scala, Swift, ReasonML and Rust these days.

Yeah F# is really nice, but the IDE support is kinda meh. Also .Net expects you to embrace nil at a lot of points which doesn't gel so nice with F#. But Swift has a worse problem with Objective-C-isms but being a first class citizen really helps as they make a lot of API's really better to use with Swift.

I wonder if it has anything to do with their being more JS developers than C# developers. Though, I imagine the average C# developer is a better programmer than the average JS programmer, but since quality is often a function of quantity, maybe there are going the later route. Or maybe it's something entirely different ;-)

> to do with their being more JS developers than C# developers.

My boss told me there was no future banging out C on small embedded processors. 25 years later there is always work because there are so few people who can still do it. When 80% of programmers can't do anything other than JavaScript they'll be more than plenty of work for the other 20%