That means it allows you to play interactive ficiton, also known as textadventures, which were implemented either by Infocom or created using the Inform compiler on a terminal, or to develop your own interactive fiction front end in C or any C-related language like C++ or Objective-C.
Fizmo is currently available as a stable version 0.8.4, released on April 9, 2017. Development began about mid-2005, with the first official version 0.6.0 being released on March 28, 2009. Version 0.8 introduced the SDL2-based interface along with proportional font display, sub-pixel rendering and support for Hi-DPI displays.
In the context of the Hadean Lands Kickstarter project, Andrew Plotkin has implemented iOS-fizmo which allows authors to package their games for the Apple App store. As an example, he also implemented The Dreamhold for the iPhone and iPad, as well as Shade – see also Reviews-on-the-Run's Shade impression – and Heliopause. There's also Jason McIntosh's adaption of The Warbler's Nest.
fizmo was written from 2005 to 2017 by Christoph Ender. Most of the GLK-interface was written by Andrew Plotkin.
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