If you don't specifically need a real VFS, you can always create an SQLite database with a simple table containing a filename and a blob containing the data. If you need more things like creation/modification date/time, you can add those columns too. You can even add a deleted column/flag if you want to be able to undelete files. And... it is cross platform.
- About a VFS library grd
- About a VFS library PMunch
- About a VFS library scippie