public static void PrintRot()
{
    IRunningObjectTable rot;
    IEnumMoniker enumMoniker;
    int retVal = GetRunningObjectTable(0, out rot);

    if (retVal == 0)
    {
        rot.EnumRunning(out enumMoniker);

        IntPtr fetched = IntPtr.Zero;
        IMoniker[] moniker = new IMoniker[1];
        while (enumMoniker.Next(1, moniker, fetched) == 0)
        {
            IBindCtx bindCtx;
            CreateBindCtx(0, out bindCtx);
            string displayName;
            moniker[0].GetDisplayName(bindCtx, null, out displayName);
            Console.WriteLine("Display Name: {0}", displayName);
        }
    }
}

[DllImport("ole32.dll")]
private static extern void CreateBindCtx(int reserved, out IBindCtx ppbc);

[DllImport("ole32.dll")]
private static extern int GetRunningObjectTable(int reserved, out IRunningObjectTable prot);

Display Name: !VisualStudio.DTE.11.0:7120
Display Name: clsid:331F1768-05A9-4DDD-B86E-DAE34DDC998A:
Display Name: !{7751A556-096C-44B5-B60D-4CC78885F0E5}
Display Name: c:usersdavedocumentsvisual studio 2012ProjectsMyProjMyProj.sln
Display Name: !{059618E6-4639-4D1A-A248-1384E368D5C3}