There is only one file type that uses the .OSDX extension:
Search Connector Description File
Installation file for a Search Connector (.SEARCHCONNECTOR-MS file) in Microsoft Windows; contains description information for a remote storage location; installs a Search Connector in Windows so users can browse remote locations in the Windows Explorer; useful for setting up remote office work environments.
If you receive an OSDX file, you can double-click it and Windows will install a Search Connector to the following directory: [user]\Searches\. You can open the installed Search Connector to browse your remote location. Note that the SEARCHCONNECTOR-MS files actually appear as folders since Windows does not display their file extension.
NOTE: The "OSD" in OSDX stands for OpenSearch Description and the "X" stands for XML, the formatting used for OSDX files.
Updated: October 10, 2011