The April 2007 issue of MSDN Magazine included an article I wrote about the excellent XmlLite parser for native C++ developers. In October of that year I wrote about the lack of a redistributable for Windows XP. Although the XML team at Microsoft told me that they hoped to provide a redistributable it never did materialize.
As a last resort I asked them whether it could be included in Windows XP Service Pack 3 so that developers could at least rely on its presence on computers with the latest service pack. Although I never received any confirmation I finally installed SP3 in a new virtual machine and look what I found:
Hope that helps.