ISSI - Version 5.1.6.1 Inno Setup Script Includes is a library of functions that can be implemented very easily into your existing setups build with Jordan Russell's Inno Setup. In the past adding some customization to Jordan Russell's Inno Setup one had to look for pieces of code and implement them into their own script. Now with this new generation of ISSI it's possible to add prefab functionality to Inno with just a few lines of code.