DoomKit
An extension for Visual Studio Code that introduces modern Doom scripting and lump support.
Heavily work in progress. DoomKit is still early in development, and only a small slice of what's planned is shared for now. More will be added as development continues.
About the mod
DoomKit is a Visual Studio Code extension that aims to bring full, proper support for developing projects on ZDoom-based ports. For now, that means support for UZDoom and Zandronum.
The extension provides language support through tmLanguage grammars, and lets you configure what you need depending on your project. ACS is supported as its own language, and BCS is supported too through an easy toggle right where the language itself is configured. Which one applies is decided by file extension by default: .acs files use the ACS language and .bcs files use the BCS language, though you're free to change it whenever you need to.
Snippets
Apart from supporting all the functions an engine provides, DoomKit also ships snippets that make it faster to write code. The built-in buildmsg function, for example, is one of the snippets provided when using the BCS language.

Feature gating
DoomKit adjusts its suggestions to the port you're targeting, gating features as needed so you stay in full control over what ends up in your project without accidentally reaching for something that isn't supported. Suggestions are limited to what's actually available for the selected port, which should help Zandronum developers in particular, since it supports a smaller feature set than most.

Targeting UZDoom means only the features UZDoom actually supports are shown, and the same applies the other way around when Zandronum is targeted instead:

