This addin will ensure that no more than 10 editors are open at a time. You can configure the number of editors that can be open at a time.
Each time you open an editor in Visual Studio the addin will check to see if the maximum number of open editor windows has been exceeded. If it has then the addin will close the least recently used editors until the number open is equal to the maximum. Visual Studio will prompt you to save changes to the editor that is closing if necessary.