SUDS is the Single User Dungeon System.
A kind of Authoring system designed for non-programmers. It is split into two parts, the Creator and the Player (both of which run only on Windows). Originally by Andy Elliot, it is now coded by Matthew Smith. It is written in Borland Delphi.
The Player includes a text parser as well as point-and-click interface, though less common verbs (such as ones implemented by authors) must be used via the text parser. The Player also has a "Hardcore" feature which removes the point-and-click elements.
The Creator uses a GUI, but only to simplify the actual creation process. The Tutorial included with the Creator walks the user through the creation of a small text adventure and teaches the various elements of the program.