Once in a while I remember .arj
And .ain which was even better but now seems to be half lost to time (no Wikipedia, just a few links repeating the same fragments of info like http://justsolve.archiveteam.org/wiki/AIN)
And .ain which was even better but now seems to be half lost to time (no Wikipedia, just a few links repeating the same fragments of info like http://justsolve.archiveteam.org/wiki/AIN)