EditorApplication.applicationPath  

static var applicationPath : String

Description

Returns the path to the Unity editor application (Read Only)

See Also: applicationContentsPath.

// This example lets you load Editor scripts
// automatically to your current working project
//
// Just place your editor scripts next to where the Unity binary
// resides.

@MenuItem("Example/Load Editor Scripts")
static function LoadEditorScripts() {
    // Get the editor folder that resides next to the Unity exec
    var appPath : String[] = EditorApplication.applicationPath.Split(char.Parse("/"));
    appPath[appPath.Length -1] = "Editor";
    var editorFolder : String = String.Join("/",appPath);
    Debug.Log("Loading editor scripts at: " + editorFolder);
    FileUtil.CopyFileOrDirectory(editorFolder,"Assets/");
}