| ShrinkIt (named NuFX archive and file format) | |
| Extension: | .SHK (regular NuFX archives), .SDK (NuFX disk images) |
| Released: | 1987? |
| Latest Release Version: | 1.0.6 (GS), 3.4 (Apple II) |
| Latest Release Date: | GS:, A2: |
| Genre: | Data compression |
| Extended From: | .BNY (Binary II envelope) .BQY (squeezed file in Binary II envelope) .BXY (NuFX in Binary II envelope) |
A NuFX archive is an archive file format that supports lossless data compression. It is usually given the file extension SHK; SDK may also be used to specify that the archive describes the entire contents of a disk.
Andy E. Nicholas designed the format as an improved replacement for the Binary II (.BNY) format, adding compression. He introduced it alongside a pkzip-like program called ShrinkIt for Apple II systems, which he later migrated to the Apple IIGS as GS-Shrinkit.
The specification was republished by Apple in its File Type Notes.[1]