Dynamics AX Build Numbers
Over on the AX Support site on MSDN, Daniel Durrer has taken the time to keep tabs on the latest builds for Microsoft Dynamics AX 4.0, 2009 and 2012. I would love to do the same thing on our site, but rather than copy his content, I'm just going to link to it and encourage you to bookmark the page so you have it as a resource when you need it:
http://blogs.msdn.com/b/axsupport/archive/2012/03/29/overview-of-ax-build-numbers.aspx
Eric Newell