There is only one file type that uses the .XFL extension:
Animate Movie Archive
An XFL file is a file saved in the Adobe XFL format, which is a compressed archive of an Animate movie's contents. It contains an XML file that specifies the structure of the movie and includes a Library folder that contains movie assets, such as images, audio, or video. XFL files are the XML-based equivalent of .FLA files.
XFL files are used to export movie content into a standard format that can imported into Adobe Animate. They are stored in a standard Zip format.
NOTE: Animate was formerly known as Flash, which was originally developed by Macromedia but then merged with Adobe in 2005. Flash became Animate in 2016.
Updated: April 11, 2017