Here is the download linkhttp://www.microsoft.com/downloads/details.aspx?familyid=7A1C9DA0-0510-44A2-B042-7EF370530C64&displaylang=en
You will need to download the free version of VC++ 2005 as well To get the tools that are compatible with it. E.G. Link. (I did not use the installer I just unpacked all the packed files in the download and found the FL_ML**** file and just renamed it to ML.exe) I unpacked the download and put it into my MASM32\BIN It will compile applications just fine. The problem is the debug extensions are not familiar to the M32 Linker.
I don't see much use for it as of yet because I have not done much work in the research department. Nor has MS provided any readily available document that I have found outlining any new features. This product was released in 2006, so it is obviously stable. Documentation is available in the MSDN Visual Studio 2005 C++ MASM Section
Here is the link to the 2005 Express editions. Don't forget all you need is the C++ edition. Its only about a couple megabyte download.http://www.microsoft.com/express/2005/download/default.aspx