Open IUP File
IUP file extension is a type of software update file used by Fritz, an online chess game program.
Fritz is a program developed in Germany, originally for Chessbase and based on Quest, ported to DOS and later to Windows.
Starting with version 13, the original engine was replaced first by Gyula Horvath's Pandix, and later with the Fritz 15, Vasik Rajlich's Rybka engine was used.
The IUP file contains data that updates the software from one version to another, which is usually automatically downloaded when there is a new software update.
If the Fritz software does not update automatically, users can manually apply the update by downloading the IUP file, locating it within the Fritz installation directory, and running the IUPgrade.exe program, which is included with the software package.
Software to open and work with a CUI file
IUP files are binary files and should not be manually attempted to be opened by the user, instead the updater should be used