VSCode (Visual Studio Code from Microsoft - https://code.visualstudio.com/) is a powerful, open-source, cross-platform lean editor built on web technologies (NodeJS, TypeScript, ElectronJS) supporting extensions (for language, tools, UI).
In regard of language support they introduced a generic JSON-RPC driven language server protocol that can use any backend (ex: NodeJS, .NET, Java ...etc) that decouples the editor bound features (completion, errors, linting, compilation, debugging, etc ...) from the language compiler implementation.
As a result, instead of using TypeScript (as for regular VSCode extensions) the language server may be written in any language/runtime (ex: stick to Oxygene, C#, Swift ..etc) as long as implements the Language Server Protocol.
With all these benefits, exposing the Elements compilers as a VSCode Language server may be a very good addition into the Elements toolbox.
Here are some relevant links in this context:
Creating Language Servers for Visual Studio Code
Language Server implemented in NodeJS & TypeScript
Language Server Protocol
OmniSharp - Official .NET, C#, Roslyn support for VSCode
OmniPascal - Delphi and Free Pascal support in Visual Studio Code
Java support for VSCode