- DP-S, Fast Splittable Pseudorandom Number Generator
- MB, Parallel Methods for Verifying the Consistency of Weakly-Ordered Architectures
aka overlay FS, translucent FS.
If a, b are directories, and m is an empty directory, then
unionfs -o cow a=RW:b m
makes m to be a combo of a and b, with a being higher priority
Writing a file into m writes it in a.
Changing a file in b writes the new version into a
Deleting a file in b causes a white-out note to be stored in a.
Unmount it thus:
fusermount -u m
None of this requires superuser.
Application: making a read-only directory into a read-write directory.
Note: IBM had a commercial version of this idea in its CP/CMS OS in the 1960s.