# dotnet/roslyn

The Roslyn .NET compiler provides C# and Visual Basic languages with rich code analysis APIs.

Repository: https://github.com/dotnet/roslyn
Canonical: https://ross.abutalabs.com/products/roslyn
Homepage: https://docs.microsoft.com/dotnet/csharp/roslyn-sdk/
Language: C#
License: MIT
License Family: permissive
Topics: roslyn, visual-basic, visual-studio, csharp, hacktoberfest
Last push: 2026-08-26T23:23:06+00:00

## Health v2 (maintenance only)
Score: 67/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 99, release rhythm 8, longevity 100
- inputs: {"age_days": 4253, "days_push": 7, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 20628, forks 4308 (observed 2026-08-28T04:11:30.294346+00:00)

## What it is
Roslyn is the open-source .NET Compiler Platform implementing the C# and Visual Basic compilers with rich code analysis APIs. It exposes compiler models (syntax trees, semantic models) so tools like IDEs, analyzers, refactoring engines, and source generators can inspect and manipulate code.

## Use cases
- build a C# code analyzer or linter
- write a Visual Studio extension with IntelliSense-like features
- generate C# source code at compile time with source generators
- parse and analyze C# syntax trees programmatically
- build a custom refactoring or code-fix tool
- implement a C# scripting host

## When to choose
- you need to parse, analyze, or transform C# or VB code
- you are building Roslyn analyzers, code fixes, or source generators
- you want IDE-grade code intelligence in your own tooling

## When to avoid
- you just need to compile .NET code (use the standard csc/dotnet build tooling)
- you are analyzing languages other than C# or Visual Basic

## Facets
- artifact type: library
- maturity: stable
- function: compiler, parser, linter, developer-tools, code-review
- domain: compilers, programming-languages, parsers, developer-tools, text-editors
- platform: dotnet, windows, cross-platform
- tags: csharp, visual-basic, code-analysis, roslyn-sdk, ide-tooling, syntax-tree, source-generators

## Member repositories
- dotnet/roslyn (main) score 67

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:30.294346+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T16:58:34.923178+00:00, confidence not recorded.
  - readme: https://github.com/dotnet/roslyn (fetched 2026-08-28T04:11:30.294346+00:00, sha 1fc51d5edd12)
  - homepage: https://docs.microsoft.com/dotnet/csharp/roslyn-sdk/ (fetched 2026-08-29T07:57:13.730512+00:00, sha b1033b4a152d)
  - site_page: https://learn.microsoft.com/en-us/lifecycle/faq/internet-explorer-microsoft-edge (fetched 2026-08-29T07:57:13.739895+00:00, sha c363b2f43d4b)
- Data as of 2026-08-30T08:39:29.467469+00:00.