IFF (Interchange File Format)

IFF was designed by Jerry Morrison at Electronic Arts in 1985 for the Amiga. The idea was a shared shell: a file was built from "chunks", each with a four-character code, a length, and then data. A reader could skip over any chunk it didn't understand, which made the format future-proof. The standard types multiplied — ILBM for images, 8SVX for audio samples, ANIM for animation.

ILBM images were painted in Deluxe Paint and 8SVX samples became instruments in early trackers. The design outlived the Amiga by decades: Apple's AIFF is built directly on IFF, Microsoft's RIFF is the same idea with the byte order reversed, and even PNG borrowed the chunk approach. One of the first formats to take "describe the data inside the data" seriously.