This ad for the Isgur Portfolio System appeared in the March 1987 issue of Antic. This software is for managing a portfolio and was available on DOS based systems, the Macintosh and the Atari ST. Antic was covering the Atari ST at this point, hence why the ad appeared there.
This kind of productivity software was not as common on the Atari ST or even on the Macintosh as it was on the PC. While each of those machines found their own niche (desktop publishing for the Mac and music and games for the Atari ST) other types of productivity, other than the basics (word processors, etc.) were not that common.
Read more: https://megalextoria.blogspot.com/2017/07/the-isgur-portfolio-system-dos.html