this is the reasoning

https://github.com/microsoft/typescript-go/discussions/411

I wonder if they did consider D language. First comment says why Rust would be a good choice "If not C#, I would have expected Rust, since that's where the rest of the ecosystem is. So, another surprise there." it seems D is missing ecosystem to be competive language?

On Monday, 8 September 2025 at 16:43:10 UTC, Neto wrote:

It's just a compiler, so any language that isn't JS or Python would work. Language choice often comes down to team preference and ecosystem.

On Monday, 8 September 2025 at 16:43:10 UTC, Neto wrote:

It is an old news now.
They decided to use Go, because it was closer to the language of their initial implementation (TypeScript).

D is expensive for production in most of the cases.
In wider terms I would say it is not production ready.
{
Yes, I know there are companies that are using it in production.
Even several big ones like Weka and Symmetry.

No, it's not enough.
}

So I don't think they were considering D at all. Most probably they had some short-list of the language that their team knows and that are suitable for the task.

Something like C#, Rust, Go, C++

And not sure if ecosystem was a significant weight in the decision.

On Monday, 8 September 2025 at 16:43:10 UTC, Neto wrote:

https://github.com/gopherjs/gopherjs

I doubt it was in the running

On Monday, 8 September 2025 at 16:51:09 UTC, Serg Gini wrote:

Why isn't D production ready?

On Monday, 8 September 2025 at 19:55:20 UTC, Neto wrote:

For this type of questions is kinda hard to prepare a short answer..
So instead of direct answer consider to check this equation:

Being production ready is a hard/complicated target..

large language = complicated
many flexible features = complicated
being focused on required important tasks = complicated
volunteer based maintenance and development = complicated
lack of business/corporation funding = complicated

So for D it is very (complicated)^^N task..

On Monday, 8 September 2025 at 20:10:52 UTC, Sergey wrote:

One has to ask why to choose a production language.

1. First one has to be aware that it exists.
   a. See Eiffel and D
   Eiffel has been in production since 1985.
   If you use the native version, it works as advertised.
   Eiffel has had great challenges playing nice with .NET, not quite there.

2. Management needs to know someone who is already using D/Eiffel.
   If the sphere of influence such as staff, related businesses, other management,
   recruiters haven't heard of D/Eiffel, that can be the end of the discussion.

3. Management needs to run a small demo project that solves a problem they have.

4. There needs to be a way to quickly spin up / train D developers, who already know C, C++, Java
   and C#.

5. There needs to be a BIG PAYOFF in one or more of the following areas:
   a. Cost, such as AWS servers.
   b. Cost as in writing new functionality.
   c. Cost as in maintaining existing code.
   d. Ease of adding in new features.
   e. Likelihood of code released to production JUST WORKS.
   f. Ease of finding D developers
   If they put out a request for 3 D developers, and they get 100 resumes,
   that will put their mind at ease that there are D developers out there.
   g. Quality of code, so that customers aren't performing QA duties.
   If code is error prone, and customers notice it, they are less likely to renew
   their contracts. They are also known to spread the word that Company X is slop job.

IMHO, if the development team uses D, OOP using Design by Contract (DbC), unit tests,
code review, volume testing, etc., the code written in D should be Production Ready.