Why is the unity folder so cluttered with IDE files

Whenever I create a new Unity project, add a C# script file and synchronize it with an external source code editor, there appears a number of .sln and .csproj files generated in the main project folder.

I wouldn’t bother it wasn’t for the fact that there’s 6 x .csproj and 2 x .sln with names like:

  • Assembly-CSharp.csproj
  • Assembly-CSharp-Editor.csproj
  • Assembly-CSharp-Editor-vs.csproj
  • Assembly-CSharp-firstpass.csproj
  • Assembly-CSharp-firstpass-vs.csproj
  • Assembly-CSharp-vs.csproj

After a solution is opened automatically by Unity, it has 3 projects with pretty similar structure - every project has an Assets folder, but seems to include a different permutation of assets.

Whether I use VS or MonoDevelop doesn’t matter. The question is:

Is this a standard project structure or did I get something wrong? Is it possible to reduce the clutter, which makes me unsure which project I should be working on, or are all these files necessary?

The reason I’m asking is there seems to be a lot of redundancy and it’s not very clear what each of these projects is responsible for.

This is the standard solution structure for a Unity project. Each one can have a number of projects in the solution. Mine usually have 6 projects in the solution. You didn’t do anything wrong, and there’s nothing you can do to reduce this. These are needed for both unity and the IDE that you’re using.

If you’re wondering why they do this, it’s due to the fact that they need to make sure that things get compiled in the correct order. You can take a look at this page for more details on the compile order. That might also help you understand what’s put in each project.

For those not wanting to go searching for what’s in each project, here’s a basic synopsis:


  • contains the files in the StandardAssets folder.


  • contains the files outside of the Editor folder.


  • contains the files inside of the Editor folder.

The projects that replace “CSharp” with “UnityScript” contain the Unity Script files in the same manner.

As for the ones ending in -vs, I’d imagine those are for the visual studio projects.