As an IT professional and starting a new job you always find yourself needing to learn the new environment around you.  Most companies don’t have much documentation or design diagrams of how their infrastructure is currently setup or how it looks.  This is pretty common with Active Directory and Exchange environments.  Sure you can always fire up Active Directory Users and Computers, Sites and Services, or Domains and Trusts … but depending on the size of the environment getting all that information can take time.  Microsoft’s Active Directory Topology Diagrammer (ADTD) can help!  Running this tool you can read your entire Active Directory structure and automatically output that information into a Visio 2003 or 2007 diagram.

All you need to do is provide a domain controller, check the information you would like the tool to look for and then just hit the Discover button.  The tool will query your AD/DNS environment and provide you with a status, which you can then click Draw! and all the information will be drawn to a Visio document.

I’ve used this tool against Windows 2000, 2003, and 2008 Active Directory installations; it also seemed to work well discovering Exchange 2003 and 2007 organizations.