As of July 2012, Microsoft has stopped selling Commerce Server. With that, Ascentium is now officially starting to sell Commerce Server and is now announcing general availability of re-branded versions of both Commerce Server 2009 and Commerce Server 2009 R2. These editions are, for the most part, absolutely identical to their Microsoft counterparts other than brand elements. One could even go so far as to run a mixed mode data center deployment between the Ascentium and Microsoft-branded versions if so-desired.
The differences are as follows for Commerce Server 2009:
These releases are licensed and supported entirely by Ascentium; if you acquired the Microsoft versions of the product, support goes through Microsoft.
Another common question that comes up is how to get more Commerce Server 2007 licenses. The easiest way to do this is to get the Ascentium-branded version of Commerce Server 2009, as Commerce Server 2007 is a discrete embedded component in that release (note that support still goes to Ascentium when licensed in this manner). However, a better story if you are running on Windows Server 2008 x64 or newer, Commerce Server 2009 R2 represents a much better story as it has no breaking changes from Commerce Server 2007 and contains numerous additional fixes and performance enhancements for running CS2007-applications in addition to supporting newer operating system, database, and developer platforms.