ahwootech/BRUTAL

A free, open source C# framework for making games, or your own game engine. Direct access to native APIs and Vulkan, with the low-level libraries around them. The foundation under Kitten Space Agency and RimWorld's Waylith engine.

C#

326

7 commits

updated Oct 15, 2026

See the code

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Kitten space agency engine, BRUTAL open sourced

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Oct 15, 2026

README

BRUTAL

BRUTAL Framework

A free, open source C# framework for making games, or your own game engine.

BRUTAL is a framework. You can make a game directly with it, or use it as the foundation for a separate engine. We made Kitten Space Agency directly on BRUTAL. Ludeon built their Waylith engine on it to move RimWorld off Unity.

At its core is a custom interop layer giving C# direct access to native APIs and libraries. Around that we've built mathematics, memory management, strings, collections, job scheduling, logging, localization, and bindings for Vulkan, GLFW, Dear ImGui, FMOD, RakNet, Jolt and Box2D. BRUTAL doesn't make the architectural decisions for you. You write your own stack. You can use whatever NuGet packages you want, including third-party ones.

It's called BRUTAL for a reason. In some ways it's much harder to use than Unity, Unreal or Godot. In other ways, particularly if you're doing something unusual, it's considerably easier. You actually have to know what you want to do first.

Why

You are only as independent as your tools are.

Developers have surrendered an extraordinary amount of control over their work to companies whose interests are not necessarily aligned with their own. We're not suggesting everyone should make their own game engine. We're suggesting every developer should have the option to, without having to spend four years building the foundations first.

What that means in practice:

  • Free, including for commercial games. No royalties. We don't want a percentage of your game's revenue. We ask for credit.
  • Open source. The source is here under an MIT-based licence. If one day we stop being accountable to developers, you can fork it and go your own way.
  • Deliberately small. We do a few low-level things well: interop, memory, concurrency, maths, strings, and bindings to native libraries, on the latest C# and Vulkan. We avoid allocations and unnecessary overhead and use unmanaged memory and unsafe code where it makes sense.
  • A foundation, like a kernel. Think of the Linux kernel and something like Ubuntu. It's not an exact comparison, but it gets the idea across. We provide the foundation and you build your own systems on top.

What BRUTAL is not

BRUTAL is not trying to be a general-purpose engine. There is no editor, no scene graph and no renderer, and we're not adding them. We push back on efforts to add more, because adding everything is how the industry ended up with the kind of engines we don't want to use. Pull requests that drift away from a clear purpose will be rejected.

Projects using BRUTAL

ProductStudioEngine (if any)
RimWorldLudeon StudiosWaylith
Kitten Space AgencyRocketWerkzDirect on BRUTAL
TorpediaRocketWerkzDirect on BRUTAL
Art of the RailRocketWerkzDirect on BRUTAL
AfterskiesFloating Origin InteractiveDirect on BRUTAL

Ludeon report 2 to 4 times the performance of the Unity build in their own tests, with the vast majority of existing mods still compatible. See their Steam announcement.

Kitten Space Agency is a free pre-alpha spaceflight simulation. It runs a solar system at real scale, and is the first major project built directly on BRUTAL. Download it on Ahwoo and see the technology yourself.

What is in the box

Each top-level folder in this repository is one library, published as a NuGet package. Reference only the ones you need.

LibraryWhat it is
Brutal.CoreBase types, attributes, platform detection, pointer helpers, Roslyn analyzers
Brutal.InteropThe custom interop layer that gives C# direct access to native APIs
Brutal.MemoryUnmanaged memory management and allocators
Brutal.CollectionsCollections that don't allocate
Brutal.StringsString building and handling without allocation
Brutal.Maths, Brutal.NumericsVector, matrix and numeric types
Brutal.ConcurrencyJob system and threading
Brutal.LoggingLogging
Brutal.LocalizationLocalization
Brutal.Vulkan, Brutal.Vulkan.Abstractions, Brutal.Vulkan.VmaVulkan bindings, abstractions and the Vulkan Memory Allocator
Brutal.OpenGlOpenGL bindings
Brutal.ShaderC, Brutal.SlangShader compilation
Brutal.Glfw, Brutal.Sdl, Brutal.Sdl.Image, Brutal.Sdl.Mixer, Brutal.Sdl.TtfWindowing and input, with SDL's image, audio mixing and font add-ons
Brutal.ImGui, Brutal.ImGui.*, Brutal.ImPlotDear ImGui and ImPlot bindings, docking branch
Brutal.Render.MeshMesh utilities
Brutal.Texture, Brutal.Texture.Abstractions, Brutal.Ktx, Brutal.Gli, Brutal.StbTexture loading, KTX and compressed formats, image decoding
Brutal.Gltf, Brutal.MeshOptimizerglTF loading and mesh optimisation
Brutal.FreeTypeFont rasterisation
Brutal.Fmod, Brutal.OpenAlAudio
Brutal.RakNetNetworking
Brutal.Jolt, Brutal.Box2D3D and 2D physics
Brutal.Monitor.Common, Brutal.Monitor.Host, Brutal.RenderDoc, Brutal.RenderDoc.ImGuiRuntime monitoring and RenderDoc capture integration
Brutal.NativeFileDialog, Brutal.NotCurses, Brutal.ZLibNative file dialogs, terminal UI, compression

Third-party notices for each library live in its LICENSES folder, Brutal.ImGui/LICENSES say.

Getting started

Prerequisites

  • .NET 10 SDK
  • A Vulkan 1.3 capable GPU with current drivers (if you render)
  • The Vulkan SDK if you want validation layers while developing
  • Windows or Linux

Your first window

Create a project and add Core and Glfw:

dotnet new console -n HelloBrutal
cd HelloBrutal
dotnet add package Ahwoo.Brutal.Core
dotnet add package Ahwoo.Brutal.Glfw

Replace Program.cs:

using Brutal.GlfwApi;
using Brutal.Numerics;

if (!Glfw.Init())
    throw new Exception("Failed to initialize GLFW");

Glfw.WindowHint(GlfwWindowHint.ClientApi, 0);
var window = Glfw.CreateWindow(new GlfwWindow.CreateInfo
{
    Title = "Hello BRUTAL",
    Size = new int2(1280, 720),
});

while (!window.ShouldClose)
    Glfw.PollEvents();

Glfw.Terminate();
dotnet run

That opens a window with no graphics API. What you add next is up to you:

  • Rendering: Ahwoo.Brutal.Vulkan.Abstractions and Ahwoo.Brutal.Vulkan.Vma for a Vulkan renderer, Ahwoo.Brutal.ShaderC to compile shaders at runtime.
  • Debug UI: Ahwoo.Brutal.ImGui and Ahwoo.Brutal.ImPlot.
  • Parallelism: Ahwoo.Brutal.Concurrency for the job system.
  • Audio and networking: Ahwoo.Brutal.Fmod, Ahwoo.Brutal.RakNet.

Questions and "how do I" threads go on the Guides and Help forum.

Building from source

This is the source for every published package. Project files, a solution and build scripts are coming. Until then use the NuGet packages, and use this repository to read and fork the code.

git clone https://github.com/ahwootech/BRUTAL.git

Licence

BRUTAL is free to use, modify and distribute, including in commercial games. There are no royalties and we don't want a percentage of your game's revenue.

The licence is based on MIT with an added attribution requirement. A game or product built with BRUTAL:

  1. includes the BRUTAL copyright notice in its credits screen, or equivalent (section 2.1)
  2. shows the BRUTAL logo before gameplay starts (section 2.2)
  3. ships NOTICE.txt alongside the product (section 2.3)

If you don't want to do that, we can arrange a separate commercial licence. We also waive the logo requirement for non-profit projects and where displaying it would be detrimental to the application's purpose.

BRUTAL is open source. There are already OSI-approved licences that allow graphical attribution. Ours is not yet OSI approved because we have not submitted it yet. We intend to, and to develop the licence with community feedback. See LICENSE.txt for the full text.

Third-party components keep their own licences. Section 4.0 points at the LICENSES folder at the root of each NuGet package; in this repository, those notices are in the LICENSES folder of each library that redistributes them.

Contributing

You can submit PRs and issues. We are a small team and maintaining a public framework is going to be a lot of work, so please be patient with us. We'll see what happens, assess the problems, and change our workflows as necessary. What won't change is BRUTAL's scope.

Before opening a PR, read CONTRIBUTING.md. It covers scope, what we expect from AI-assisted contributions, the contribution grant in section 5.0 of the licence, and the sign-off every commit needs. Small changes you understand and have tested, with a clear purpose, are the ones that will get merged.

Community

Credits

BRUTAL was made by the RocketWerkz Enterprise team and others, named in CONTRIBUTORS.md. When we talk about wanting credit for BRUTAL, these are the people we are talking about.

BRUTAL is Copyright (c) 2024 Ahwoo Limited.

ahwootech/BRUTAL

A free, open source C# framework for making games, or your own game engine. Direct access to native APIs and Vulkan, with the low-level libraries around them. The foundation under Kitten Space Agency and RimWorld's Waylith engine.

C#

326

7 commits

updated Oct 15, 2026

See the code

See what people are saying

SourceMessageScoreDate

Kitten space agency engine, BRUTAL open sourced

2

Oct 15, 2026

README

BRUTAL

BRUTAL Framework

A free, open source C# framework for making games, or your own game engine.

BRUTAL is a framework. You can make a game directly with it, or use it as the foundation for a separate engine. We made Kitten Space Agency directly on BRUTAL. Ludeon built their Waylith engine on it to move RimWorld off Unity.

At its core is a custom interop layer giving C# direct access to native APIs and libraries. Around that we've built mathematics, memory management, strings, collections, job scheduling, logging, localization, and bindings for Vulkan, GLFW, Dear ImGui, FMOD, RakNet, Jolt and Box2D. BRUTAL doesn't make the architectural decisions for you. You write your own stack. You can use whatever NuGet packages you want, including third-party ones.

It's called BRUTAL for a reason. In some ways it's much harder to use than Unity, Unreal or Godot. In other ways, particularly if you're doing something unusual, it's considerably easier. You actually have to know what you want to do first.

Why

You are only as independent as your tools are.

Developers have surrendered an extraordinary amount of control over their work to companies whose interests are not necessarily aligned with their own. We're not suggesting everyone should make their own game engine. We're suggesting every developer should have the option to, without having to spend four years building the foundations first.

What that means in practice:

  • Free, including for commercial games. No royalties. We don't want a percentage of your game's revenue. We ask for credit.
  • Open source. The source is here under an MIT-based licence. If one day we stop being accountable to developers, you can fork it and go your own way.
  • Deliberately small. We do a few low-level things well: interop, memory, concurrency, maths, strings, and bindings to native libraries, on the latest C# and Vulkan. We avoid allocations and unnecessary overhead and use unmanaged memory and unsafe code where it makes sense.
  • A foundation, like a kernel. Think of the Linux kernel and something like Ubuntu. It's not an exact comparison, but it gets the idea across. We provide the foundation and you build your own systems on top.

What BRUTAL is not

BRUTAL is not trying to be a general-purpose engine. There is no editor, no scene graph and no renderer, and we're not adding them. We push back on efforts to add more, because adding everything is how the industry ended up with the kind of engines we don't want to use. Pull requests that drift away from a clear purpose will be rejected.

Projects using BRUTAL

ProductStudioEngine (if any)
RimWorldLudeon StudiosWaylith
Kitten Space AgencyRocketWerkzDirect on BRUTAL
TorpediaRocketWerkzDirect on BRUTAL
Art of the RailRocketWerkzDirect on BRUTAL
AfterskiesFloating Origin InteractiveDirect on BRUTAL

Ludeon report 2 to 4 times the performance of the Unity build in their own tests, with the vast majority of existing mods still compatible. See their Steam announcement.

Kitten Space Agency is a free pre-alpha spaceflight simulation. It runs a solar system at real scale, and is the first major project built directly on BRUTAL. Download it on Ahwoo and see the technology yourself.

What is in the box

Each top-level folder in this repository is one library, published as a NuGet package. Reference only the ones you need.

LibraryWhat it is
Brutal.CoreBase types, attributes, platform detection, pointer helpers, Roslyn analyzers
Brutal.InteropThe custom interop layer that gives C# direct access to native APIs
Brutal.MemoryUnmanaged memory management and allocators
Brutal.CollectionsCollections that don't allocate
Brutal.StringsString building and handling without allocation
Brutal.Maths, Brutal.NumericsVector, matrix and numeric types
Brutal.ConcurrencyJob system and threading
Brutal.LoggingLogging
Brutal.LocalizationLocalization
Brutal.Vulkan, Brutal.Vulkan.Abstractions, Brutal.Vulkan.VmaVulkan bindings, abstractions and the Vulkan Memory Allocator
Brutal.OpenGlOpenGL bindings
Brutal.ShaderC, Brutal.SlangShader compilation
Brutal.Glfw, Brutal.Sdl, Brutal.Sdl.Image, Brutal.Sdl.Mixer, Brutal.Sdl.TtfWindowing and input, with SDL's image, audio mixing and font add-ons
Brutal.ImGui, Brutal.ImGui.*, Brutal.ImPlotDear ImGui and ImPlot bindings, docking branch
Brutal.Render.MeshMesh utilities
Brutal.Texture, Brutal.Texture.Abstractions, Brutal.Ktx, Brutal.Gli, Brutal.StbTexture loading, KTX and compressed formats, image decoding
Brutal.Gltf, Brutal.MeshOptimizerglTF loading and mesh optimisation
Brutal.FreeTypeFont rasterisation
Brutal.Fmod, Brutal.OpenAlAudio
Brutal.RakNetNetworking
Brutal.Jolt, Brutal.Box2D3D and 2D physics
Brutal.Monitor.Common, Brutal.Monitor.Host, Brutal.RenderDoc, Brutal.RenderDoc.ImGuiRuntime monitoring and RenderDoc capture integration
Brutal.NativeFileDialog, Brutal.NotCurses, Brutal.ZLibNative file dialogs, terminal UI, compression

Third-party notices for each library live in its LICENSES folder, Brutal.ImGui/LICENSES say.

Getting started

Prerequisites

  • .NET 10 SDK
  • A Vulkan 1.3 capable GPU with current drivers (if you render)
  • The Vulkan SDK if you want validation layers while developing
  • Windows or Linux

Your first window

Create a project and add Core and Glfw:

dotnet new console -n HelloBrutal
cd HelloBrutal
dotnet add package Ahwoo.Brutal.Core
dotnet add package Ahwoo.Brutal.Glfw

Replace Program.cs:

using Brutal.GlfwApi;
using Brutal.Numerics;

if (!Glfw.Init())
    throw new Exception("Failed to initialize GLFW");

Glfw.WindowHint(GlfwWindowHint.ClientApi, 0);
var window = Glfw.CreateWindow(new GlfwWindow.CreateInfo
{
    Title = "Hello BRUTAL",
    Size = new int2(1280, 720),
});

while (!window.ShouldClose)
    Glfw.PollEvents();

Glfw.Terminate();
dotnet run

That opens a window with no graphics API. What you add next is up to you:

  • Rendering: Ahwoo.Brutal.Vulkan.Abstractions and Ahwoo.Brutal.Vulkan.Vma for a Vulkan renderer, Ahwoo.Brutal.ShaderC to compile shaders at runtime.
  • Debug UI: Ahwoo.Brutal.ImGui and Ahwoo.Brutal.ImPlot.
  • Parallelism: Ahwoo.Brutal.Concurrency for the job system.
  • Audio and networking: Ahwoo.Brutal.Fmod, Ahwoo.Brutal.RakNet.

Questions and "how do I" threads go on the Guides and Help forum.

Building from source

This is the source for every published package. Project files, a solution and build scripts are coming. Until then use the NuGet packages, and use this repository to read and fork the code.

git clone https://github.com/ahwootech/BRUTAL.git

Licence

BRUTAL is free to use, modify and distribute, including in commercial games. There are no royalties and we don't want a percentage of your game's revenue.

The licence is based on MIT with an added attribution requirement. A game or product built with BRUTAL:

  1. includes the BRUTAL copyright notice in its credits screen, or equivalent (section 2.1)
  2. shows the BRUTAL logo before gameplay starts (section 2.2)
  3. ships NOTICE.txt alongside the product (section 2.3)

If you don't want to do that, we can arrange a separate commercial licence. We also waive the logo requirement for non-profit projects and where displaying it would be detrimental to the application's purpose.

BRUTAL is open source. There are already OSI-approved licences that allow graphical attribution. Ours is not yet OSI approved because we have not submitted it yet. We intend to, and to develop the licence with community feedback. See LICENSE.txt for the full text.

Third-party components keep their own licences. Section 4.0 points at the LICENSES folder at the root of each NuGet package; in this repository, those notices are in the LICENSES folder of each library that redistributes them.

Contributing

You can submit PRs and issues. We are a small team and maintaining a public framework is going to be a lot of work, so please be patient with us. We'll see what happens, assess the problems, and change our workflows as necessary. What won't change is BRUTAL's scope.

Before opening a PR, read CONTRIBUTING.md. It covers scope, what we expect from AI-assisted contributions, the contribution grant in section 5.0 of the licence, and the sign-off every commit needs. Small changes you understand and have tested, with a clear purpose, are the ones that will get merged.

Community

Credits

BRUTAL was made by the RocketWerkz Enterprise team and others, named in CONTRIBUTORS.md. When we talk about wanting credit for BRUTAL, these are the people we are talking about.

BRUTAL is Copyright (c) 2024 Ahwoo Limited.