Today we’re excited to announce and get some early feedback with TypeScript 2.9’s Release Candidate. To get started with the RC, you can access it through NuGet, or use npm with the following command:
npm install -g typescript@rc
You can also get editor support by
Downloading for Visual Studio 2015 (with Update 3)
Downloading for Visual Studio 2017 (for version 15.2 or later)
Following directions for Visual Studio Code and Sublime Text.