NTVS, short for Node.js Tools for Visual Studio, offers Node.js developers a fully featured IDE complete with Intellisense, package management, profiling, and debugging.
Debugging support is offered both locally and remotely. In the case of remote debugging, MacOS and Linux are also supported. Much of the debugger work comes from Dmitry Tretyakov of Clickberry.
Package management is handled via NPM, also known as Node Packaged Modules. Bart Read from Red Gate provided the UI for this feature.
The reason so many third parties are showing up is that multiple projects to support Node.js were started at roughly the same time. Furthermore, they were largely based on Python Tools for Visual Studio (PTVS). So when the PTVS team at Microsoft realized what was happening they decided to solicit contributions. A Reddit user by the name of dinov explains,
I work at Microsoft on NTVS and it is built primarily by Microsoft. But we've also been collaborating with others before the release.
While working on it we saw several disjoint efforts to produce Node.js support for VS including RedGate's Visual Node and another "NTVS" made by some individuals. We reached out to them before the release, gave them access to the code, and were excited to accept their contributions. The most notable contribution is the NPM support which is a pretty significant feature from RedGate.
Because it uses the built-in JavaScript editor, NTVS requires Visual Studio Professional or higher.