Microsoft's Active Directory has been around for a very long time, since its debut as part of Windows Server 2000. Since those early days, there have been plenty of changes, improvements and schema updates to improve the platform which has become so popular, and a key component of most Windows based environments. However, there hasn't been much of a focus on ways to clean up the Organizational Units (OUs) and objects inside them; that is left up to you to do for yourself.