Earlier quoted context omitted.
Jet-brains products have a gigantic plugin ecosystem that allows you to add whatever functionality you want..
Well, not everything. Language support cannot be implemented by relying on an external service (like the typescript service), it has to be implemented in a very specific way. They are extensible, sure, but not very flexible.
> This assistance can be provided either by IntelliJ IDEA itself, or based on the data from
> the built-in TypeScript compiler, or through integration with the TypeScript Language Service.
They bundle whatever latest TS is available when the product is created or let you point to your own installation. "Use TypScript Service" is marked "experimental", so letting the IDE use the external service for things it traditionally figured out on its own to provide coding assistance is being worked on.[0] https://www.jetbrains.com/help/idea/2016.2/typescript-suppor...