# CosmosOS/Cosmos

Cosmos is an operating system "construction kit". Build your own OS using managed languages such as C#, VB.NET, and more!

Repository: https://github.com/CosmosOS/Cosmos
Canonical: https://ross.abutalabs.com/products/cosmosos-cosmos
Homepage: https://www.goCosmos.org
Language: C#
License: BSD-3-Clause
License Family: permissive
Topics: hacktoberfest
Last push: 2026-08-23T19:42:13+00:00

## Health v2 (maintenance only)
Score: 87/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 64, longevity 100
- inputs: {"age_days": 4290, "days_push": 10, "days_rel": 26, "gap_med": null, "n_releases_24m": 1}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3188, forks 581 (observed 2026-08-28T04:07:48.080038+00:00)

## What it is
Cosmos is an operating system construction kit that lets developers build bare-metal OS kernels using .NET languages like C#, VB.NET, and F#. It includes the IL2CPU compiler that converts IL code into native machine code, plus a standard library providing filesystem, graphics, networking, and audio primitives.

## Use cases
- build a hobby operating system in C#
- write a bare-metal kernel without assembly
- learn OS development with managed code
- compile C# to run directly on hardware
- create a custom bootable OS from .NET code
- experiment with low-level memory and assembly access from C#

## When to choose
- you want to write an OS in C# or another .NET language instead of C or assembly
- you are learning operating system fundamentals with a managed-language toolkit
- you need a ready-made kernel base with filesystem, graphics, and networking primitives

## When to avoid
- you need a production-grade OS with mature drivers and hardware support
- you want to develop an OS in C, Rust, or assembly with full low-level control
- you need a general-purpose .NET runtime for applications rather than OS development

## Facets
- artifact type: framework
- maturity: active
- function: compiler, programming-language, embedded, file-system, graphics, networking, sdk
- domain: operating-systems, compilers, developer-tools, embedded-systems
- platform: dotnet, cpp, windows, cross-platform
- tags: operating-system-development, il2cpu, bare-metal, csharp, kernel-development, managed-code, linux

## Member repositories
- CosmosOS/Cosmos (main) score 87

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:48.080038+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 2026-08-30T07:24:58.214002+00:00, confidence not recorded.
  - readme: https://github.com/CosmosOS/Cosmos (fetched 2026-08-28T04:07:48.080038+00:00, sha c47d320a3c20)
  - homepage: https://www.goCosmos.org (fetched 2026-08-29T09:38:47.792894+00:00, sha 54636a6ebedd)
- Data as of 2026-08-30T08:39:29.467469+00:00.