Inform is a design system for interactive fiction, a new medium for writers which began with adventure games in the late 1970s and is now used for everything from literary narrative fiction through to plotless conceptual art, and plenty more adventure games too. Since its introduction in 1993, Inform has become a standard tool.
Alan is one of the most easy to use tools specialized for creating works of Interactive Fiction, a.k.a text adventures. It's focus has always been on the authoring aspects.
Hugo is a complete design system for developing interactive fiction. It has been used for creating classic text adventure games in the Infocom tradition, for developing commercial games, and for prototyping other applications. In addition to an extremely sophisticated full-sentence-cognizant interface, Hugo also allows a developer to incorporate graphics and video (which are optional for those who lack either the hardware or inclination to view them) as well as sound effects, music, and mouse control.
TADS is a free-ware programming system that can help you create high-quality interactive fiction.
Main IF Archive
This is the main repository of the IF archive. The archive contains numerous game engines and sample games.
264 IF games in 45 categories.
Numerous tutorials and information on playing and creating IF games.
IFCollab, a.k.a. the IF Collaborators List, is a webpage that helps connect IF authors, programmers, and artists up with each other.
IF Game Engines
The main game folder on the IF archive. Each game engine is under its respective folder.
IF Scott Adams
The Scott Adams folder on the IF archive.
Interactive Fiction using hypertext language.
IF Comp 2007
Competition site for short text adventures.