StuffIt is the de-facto standard for file archiving and compression on Mac OS before OS X. Most old Macintosh software is preserved in StuffIt format, but a format change in StuffIt 5 makes archives created in this version unreadable in older versions of StuffIt. Since StuffIt 3.5 is the last version that works on System 6, many archives cannot be opened on compact Macs running System 6.
ReStuff is a SaaS that automatically converts StuffIt version 4 & 5 archives to a format readable in StuffIt 3.
Current server status: Waiting for a file to be uploaded...
Archives converted: 76
This service can only process one file at a time, but all files are put into a queue so your file will be processed in the order it was uploaded.
Though I can't imagine anyone actually needing to convert sensitive StuffIt archives from a modern format to an archaic one as this tool does (private files preserved in old StuffIt formats can be extracted privately by modern tools on one's own computer), one should not upload sensitive files to this tool. However, files are deleted as soon as the conversion process completes and converted archives are deleted a half hour after conversion, which can only be downloaded by the user that uploaded them unless the private URL is given to someone else before the file is deleted.
This is a free service created and operated by joshua stein (@jcs). Check out my C Programming on System 6 video series and join me and others in the #cyberpals IRC channel on the freenode network.