There is only one file type that uses the .XLNK extension:
XML Shortcut File
Shortcut or "link" to another file that uses XML formatting; similar to a .LNK file, but can used on multiple platforms due to its XML-based structure; contains the path to the target file within the "TargetFile" tag in the XML.
Read more about the XLNK file format.
Updated: June 20, 2008