Timeworks Publisher (Publish It! in the U.S.) is an early-1990s desktop publishing program for Windows published by Timeworks, released originally in the U.K. It used the extension .dtp, but its files were not compatible with PageMagic by NEBS, even though that program used the same extension. If you run the two words of the U.S. program title together, you might wind up with a Scunthorpe problem with dirty-word filters.
One way to distinguish Timeworks/Publish It! files from the similarly-named PageMagic files is that file detectors such as DROID may detect PageMagic files as OLE2 (Microsoft Compound File), while Timeworks/Publish It! files are not detected this way.