This was IBM's E editor.. It was a replacement of MS Edit.. It was bundled with PC DOS and OS/2... It was actually quite a powerful text editor for its time... Its modern descendants and clones still exist.. Though most of them are proprietary.

https://s3.toot.io/system/media_attachments/files/111/102/678/105/749/521/original/aff62d574954d684.png