Download the latest Dev Kit:



User Kit

Prepackaged releases which install automatically and allow you to build your own operating systems with Cosmos and Visual Studio.

Dev Kit (Developer Kit)

Important: When using the Dev Kit, the NuGet packages are prerelease. NuGet doesn’t have a way of specifying floating versions including prerelease in the dependencies, so you need to update the packages to the Dev Kit version manually in your project.

In addition to the User Kit prerequisites, Dev Kit also needs these:

  • Visual Studio 2017 Workload: Visual Studio Extension Development
  • Inno Quick Start Pack (Free) – Install with defaults, keep Preprocessor option checked

The Dev Kit allows you to build your own operating systems, and also directly work in COSMOS source as well. Installation simply requires running a .bat file after each source sync.