.SIT

Introduction

StuffIt was the standard archiver on the classic Mac OS. Raymond Lau wrote the first version in 1987, and it was later sold by Aladdin Systems. Mac software, fonts and documents were passed around as .sit files for well over a decade, often inside a BinHex .hqx file for sending by email. Unlike most archivers, StuffIt kept each file’s Mac resource fork, type and creator codes, which classic Mac files needed.

The format was never published, and later versions changed it more than once; the newer StuffIt X format uses the extension .sitx. Free tools read most files through reverse engineering.

Structure

Two main layouts share the .sit extension:

• Classic StuffIt, from the early versions up to 4.x: the file starts with SIT!, followed by the number of entries and the archive length, and the text rLau at offset 10. Each entry then has a header with the Mac file name, type and creator, the compression method and sizes of the data and resource forks, followed by the two forks.
• StuffIt 5: the file starts with readable text beginning StuffIt (c)1997- and naming Aladdin Systems, then a binary header and entries for files and folders.

Links