Welcome to the .NET Compiler Platform ("Roslyn")

The .NET Compiler Platform ("Roslyn") provides open-source C# and Visual Basic compilers with rich code analysis APIs. You can build code analysis tools with the same APIs that Microsoft is using to implement Visual Studio!

Try new language and IDE features

Just want to provide feedback on new language features and IDE features?
  • Try out Visual Studio 2015 Preview, which has our latest features built-in.
  • You can also try April's End User Preview, which installs on top of Visual Studio 2013.
    • (note: this VS 2013 preview is quite out of date, and is no longer updated)

Build tools that understand C# and Visual Basic

Get started building diagnostics, code fixes, refactorings and other code-aware tools!

  1. Set up a box with Visual Studio 2015 Preview. Either...
  2. Install the Visual Studio 2015 Preview SDK. You'll need to do this even if you're using the Azure VM image.
  3. Install the SDK Templates VSIX package to get the Visual Studio project templates.
  4. Install the Syntax Visualizer VSIX package to get a Syntax Visualizer tool window to help explore the syntax trees you'll be analyzing.
Or, you can grab the latest NuGet Roslyn compiler package. From the NuGet package manager console:

Install-Package Microsoft.CodeAnalysis -Pre

Source code

  • Clone the sources:
git clone https://git01.codeplex.com/roslyn

Get started


Some of the best ways to contribute are to try things out, file bugs, and join in design conversations. Looking for something to work on? The list of up-for-grabs issues is a great place to start.

Last edited Nov 25 at 10:09 PM by lwischik, version 39