# sq/JSIL

CIL to Javascript Compiler

Repository: https://github.com/sq/JSIL
Canonical: https://ross.abutalabs.com/products/jsil
Homepage: http://jsil.org/
Language: C#
License: NOASSERTION
License Family: other
Archived: true
Last push: 2018-02-28T04:57:28+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 5624, "days_push": 3108, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, archived, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1733, forks 238 (observed 2026-08-28T04:05:28.946860+00:00)

## What it is
JSIL is a compiler that transforms .NET CIL bytecode into readable, standards-compliant JavaScript that runs in browsers or other JavaScript runtimes. It supports most .NET languages (C#, VB.NET, partial F#) and much of the .NET base class library, including XNA games via FNA.

## Use cases
- compile a C# application to JavaScript
- port an XNA game to run in the browser
- run .NET libraries in a web browser
- convert VB.NET code to JavaScript
- transpile .NET bytecode to cross-browser JS

## When to choose
- you have existing .NET/C# code or games you want to run in a browser without rewriting
- you need readable, debuggable generated JavaScript rather than opaque output
- you rely on broad .NET runtime features like pointers or P/Invoke

## When to avoid
- you are starting a new web project from scratch - write JavaScript or TypeScript directly
- you need actively developed tooling with modern .NET (Core/5+) support
- you need guaranteed bug-free compilation - the project is in partial maintenance mode

## Facets
- artifact type: cli-tool
- maturity: maintenance
- function: compiler, developer-tools
- domain: compilers, web-development, developer-tools
- platform: windows, cross-platform, browser
- tags: cil-to-javascript, dotnet, transpiler, xna, webassembly-adjacent

## Member repositories
- sq/JSIL (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:28.946860+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 2026-08-30T03:31:28.177082+00:00, confidence not recorded.
  - readme: https://github.com/sq/JSIL (fetched 2026-08-28T04:05:28.946860+00:00, sha 36432e81c2cd)
  - homepage: http://jsil.org/ (fetched 2026-08-29T11:08:14.132557+00:00, sha 81a62577ff90)
- Data as of 2026-08-30T08:39:29.467469+00:00.