Glulxe is an interpreted implementation of the Glulx portable Interactive Fiction VM, like the Z-machine but using the Glk API. Unlike the Z-machine, it uses 32-bit data and addresses, so it can handle game files up to four gigabytes long. Also unlike the Z-machine, it has native support for Glk I/O, so game files can use any capability Glk provides. However, like the Z-machine, you can write games in the Inform language and compile them to Glulx game files.
Lich is a cross-platform multithreaded interpreter meant exclusively for use with text-based MUDs. Its primary goal is to provide a dynamic and extensible framework that offers advanced users the ability to customize the application and its functionality to their needs while remaining accessible and useful to the majority of players. It supports scripting in Ruby, Simutronics "Wizard", and, in Unix environments, any language with an interpreter program.
The Z-machine Preservation Project is a Java implementation of the Z-machine (Java version >= 5 is required) specification. This Z-code interpreter can be run either as a standalone application or as an applet within a Web browser. It runs Interactive Fiction created by Infocom as well as those compiled with Inform, and targets all existing story file versions. Features include saving the game state, multimedia support (graphics, sound effects, meta data), colored and styled text, undo, and timed input as well as support for different languages. Games in the Inform 7 release format are supported as well (Treaty of Babel specification).