ADRIFT (short for Adventure Development and Runner - Interactive Fiction Toolkit) is a free Windows 95/98/NT application for creating text adventures.
Adventure Game Toolkit (AGT) is an old freeware text adventure creation system. It's the successor to the Generic Adventure Game System (GAGS).
Adventure Language, one of the authoring systems that requires less syntax when programming text adventures. This makes ALAN easier to learn.
Glulx is a portable VM, like the Z-machine. Unlike the Z-machine, it uses 32-bit data and addresses, so it can handle game files up to four gigabytes long. Also unlike the Z-machine, it has native support for Glk I/O, so game files can use any capability Glk provides. However, like the Z-machine -- again -- you can write games in the Inform language and compile them to Glulx game files.
The Graphic Adventure Creator (GAC to its friends) is a piece of software by Incentive Software Ltd that allows you to make illustrated text adventures.
Inform is a system for creating adventure games that can be played on almost any computer, from personal organisers to mainframes, with the aid of 'interpreter' programs.
The second generation of Quill, better known as Professional Adventure Writer (PAW), included an enhanced parser that
understood adjectives, adverbs, pronouns, conjugations and prepositions as well as verbs and nouns. It was produced in two versions. The Editor version (e.g. Spectrum) included the ability to split the screen and have pictures in the upper section and text in the lower section. The Compiler version (e.g. CP/M) compiled databases from source files and didn't have any picture capability - the compiler was written in C.
A later development of the PAW Compiler version allowed the screen to be split and for pictures to be displayed in the upper section. Each picture was a separate disk file.
The Quill (in the US sold as "Adventure Writer") is an adventure writing utility from Gilsoft. Originally it could only create text adventures but with the addition of The Illustrator it could also draw graphics.
This category also covers the Quill compatible adventure writer WinQuill.
The Text Adventure Development System has been created to ease the development of text-based interactive fiction.