Anyone come across some software that works with these audio (lossless) files?

I havent found any audio related extentions, only these:

FIL ACL For Windows Data
FIL Application Generator File Template
FIL Cardbox Database
FIL dBASE Files List Object
FIL File List
FIL ProWORX Nxt Format Export (Schneider Electric)
FIL WordPerfect Overlay (Corel)
FIL ABAQUS File (ABAQUS, Inc.)

Sure it's not .flac or been misnamed?

No its .fil, just not very well known at all. Thinking of it, a maybe a format developed 'in-house' as the local commercial radio station I work at has all of their music stored in this lossless format.

Just came across this thread, and it looks like the .fil extension is used by certain databases.
See here:
http://filext.com/alphalist.php?extstart=%5EF