There is often confusion about what Roslyn is and why it would be used with F#. This project has no relation to the Roslyn the C# Compiler. ProtoWorkspace is implementing a Roslyn Workspace from the Microsoft.CodeAnalysis API to take advantage of its capabilites for managing projects, solutions, document tracking, dirty buffers, and its infrastructure for implmenting editor tooling features (e.g. intellisense, refactoring, code fixes). The workspace for F# needs to be built from the ground up as the existing Roslyn workspaces are incompatible with F#.