DM4
From IFWiki
The primary source of information about Inform is the Designer's Manual, fourth edition, often known as the DM4. it can be found on http://www.inform-fiction.org/manual/index.html
The primary source of information about Inform is the Designer's Manual, fourth edition, often known as the DM4. it can be found on http://www.inform-fiction.org/manual/index.html