Download last version of Mirus Legacy on the downloads tab.
Would you like to see the newer codebase?


Welcome to the home of Mirus, an awesome hobby operating system written in C# using Cosmos. Mirus aims to be easy to use, powerful, secure, scale able, and great for network infrastructures.

It is one of the oldest existing operating systems of its type, dating back to nearly 2008 (or at least early 2009). The project has gone through many different names and revisions, leading up to Mirus. It was only recently released as open-source, however.

Mirus is mainly developed by its creator, Joshua Beitler - a wingnut American who has a large problem with goldfish. It is a member of the Open Cosmos Alliance, a group of Cosmos based operating systems who work together for equality and standard in the niche that Cosmos basically dominates.


Mirus has an IRC channel on Freenode (, called #Mirus, where you can go to chat with the devs, get quick help, or have fast paced dating games with the mod-bots. If you have any trouble with the system, it is advisable to ask your question here before asking elsewhere, as its most likely to be answered by the Joshinator and his Android phone of magic. (Meaning that the we're nearly always online)

Getting Source

Since we use TFS and Codeplex, getting the Mirus source is quite easy. Click the "Source Code" tab on the nav bar to get to a source view, and click "download" near the top-right corner of the page. You can also click "history" on the top-left to get a list of recent commits and commit messages, in case you want to time travel a bit.

The source you download is distributed in a .ZIP, which you should unzip with a tool like WinRAR (make sure to pay for the license xD), 7Zip (our preference), or Windows Explorer is you are on Vista or above. The main solution is called "Mirus.sln", and resides in the "src" directory. Make sure you meet the dependencies before trying to build, otherwise you will get a nasty error message.


Its really simple to build Mirus, thanks to the technologies we use. Open Mirus.sln in Visual Studio 2010 (do not use 2012). Assuming you have all the dependencies met, you can simply hit the "Debug and Run" menu item or button on your toolbar. If you want, you can perform a clean build by clicking "Build" and then hitting "Rebuild Solution". Then follow the first step.

To build the included Cosmos source, open the "cosmos" directory and run "install.bat" as administrator. Provided you meet Cosmos' dependencies, it will build and install the Visual Studio plugins and templates you need to run it.

Last edited Aug 25, 2013 at 11:23 PM by joshbeitler, version 78