Development Tools

Interactive Fiction Authoring with IFML
XML based markup language and game playing engine for creating and playing text adventures. Uses a screenplay metaphor. Authors create scenes, dialogs, props, and characters.
http://ifml.sourceforge.net

JACL Adventure Creation Language
JACL is an interpreted computer language for creating web-based adventure games. This site contains downloadable software, documentation and sample games.
http://jacl.sourceforge.net/

QML
The Quest Markup Language is a free Choose-Your-Own-Adventure system. The XML-based games can have images, sound, states to check, and random events.
http://questml.com/

ValerieMates
Program for creating choose your own adventure games.
http://www.valeriemates.com/interactive_story.html