That would be DirOpus 4, I've used that for many years.
Others worth mentioning: Scalos 1.2d, Filemaster 3.0, JanoEditor, SnoopDOS, Scala, DPaint V, Imagine, ArtPro, WHDLoad, AMOS, Blitz Basic 2, HippoPlayer, Delitracker, Executive, YAM and lots more.
