Wolfram Language (nee Mathematica) support for Microsoft Visual Studio Code.
It is in its early development stages, so not quite ready to relase a 1.0 to the Extensions Marketplace yet. Lots of boilerplate from yo code still in here, &c. I've put it up in this state in case someone is interested in using it as-is, or perhaps in helping out.
It presently includes symbol definitions from version 11.2 of Mathematica as well as other simple syntactic support.
Mathematica / wolframscript 11.0+
For lots of detail, see the file distributed with this extension.