An mxl file extension is related to PackRat information manager for Microsoft Windows.
There is one other file type using
the MXL file extension!
.mxl - Compressed MusicXML music notation file
MXL file extension - PackRat 5.0 support data
What is mxl file? How to open mxl files?
File type specification:
The mxl file extension is associated with PackRat 5.0, an information manager for Windows, developed by Polaris Software.
The program is discontinued and no longer supported although it seems it was fairly popular product.
This mxl file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.