The first sentence of that article says the language "has been open sourced a few weeks ago". Moonbit is on Github with SSPL, so not quite open source.

Depends on the ecosystem. There are lots of scientific and engineering tools with their own languages. However National Instruments or Mathworks are not going to go away overnight.

is moonbit charging? I can't seem to find that on their site.

Separately, it seems like not a terrible plan. Better than eg hoping that Google and Oracle continue to care about the languages and runtimes they own. Go seems reasonably well used inside Google but Flutter is an open question, and the future of the jvm seems fraught with Oracle as its steward.

Actually, I thought the same about flutter. As it seem to be a huge effort to maintain and further develop it. Even Dart seems to be only used for flutter development. The technology behind flutter is complex, similar to react native. If Google or Facebook would stop support for these tools, I think, it would be highly challenging for the open source community alone to maintain it. Facebook uses RN as part of their core products. However, I don't see the incentive for Google to maintain Flutter...

> is moonbit charging?

I assume GP refers to the license of MoonBit, SSPL + exceptions, which is not generally considered fully open source.

https://www.moonbitlang.com/blog/compiler-opensource#why-a-r...

Usually this type of license is used to keep more profit options open, but it will slow down adoption.