There is only one file type that uses the .XSP extension:
Kodi Smart Playlist File
Song or video playlist used by Kodi, a free software multimedia player; may contain a list of specific audio and video files to play, or may store criteria for the types of media to play (e.g., play Rock music or all 90s music); can specify songs, albums, movies, TV shows, and other types of media.
XSP files should be placed in the Userdata directory for the Kodi installation for them to be read by the program.
XSP files use an XML text format. Therefore, you can create them with any text editor and then place them in the Userdata directory.
NOTE: Kodi was previously known as XBMC.
Updated: January 25, 2015