ULX file extension - Glulx data file
What is ulx file? How to open ulx files?
File type specification:
The ULX file extension is associated with the Glulx and used for its data files.
Glulx is a portable VM, like the Z-machine. 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 -- again -- you can write games in the Inform language and compile them to Glulx game files.