An .sb file is the file format used to store projects created in the Scratch programming language editor up to version 1.4. sb is no longer used in the current version of Scratch and was replaced by the .sb2 file in Scratch 2.0.
The .sb file is divided into four sections.
The 10-byte header contains the ASCII string 'ScratchV02' in versions higher than 1.2, and contains the string 'ScratchV01' in versions 1.2 and below.
Encodes the length of the project's infoObjects. A four-byte long, 32-bit, big-Endian integer.
A dictionary-format data section. It contains the following keys:
A table with the Stage as the root. All objects in the program are stored here as references.