Inform

Inform is a design system specifically engineered for writing interactive fiction and text adventure games. Based on natural language programming principles, it allows authors to construct complex virtual worlds using prose that closely resembles standard English rather than traditional programming syntax. The engine processes these rules to build a parser and simulation model for the text environment, handling object interactions, spatial relationships, and non-player character behaviors.

Originally developed by Graham Nelson, the tool is primarily targeted at Linux platforms in this release and utilizes a dual-licensing scheme under the GNU General Public License version 3.0 and the Artistic License 2.0. Authors write their narrative source files within the environment, which then compiles the text into playable stories compatible with standard interactive fiction interpreters. The system requires familiarity with its specialized design methodology and rule-based logic structure to effectively manage game state and narrative flow.