For a first simple installation of your application you can confine yourself to a simple parameter alone tool.  But when your application evolves you soon need more functionality, for instance to configure a browser, start and stop services, use Office automation objects, check serial numbers, convert files or install third party software.

Vendors of installation tools recognize this problem, and because they do not want to lose market share, quickly after launching their first product they start adding some ad-hoc scripting functions to their tool.  Programmers are not really helped by this ad-hoc approach; they are forced to master this home-made scripting language. Of course those companies sell this language as something ‘special made for installation”, but whatever fancy description they use, it is not the language a developer likes. Most programmers have better things to do, they must learn a total new language, loaded with idiosyncrasies.
Learning this ad-hoc computer language costs a lot of extra effort, it is easy to overlook mistakes when you use it, and there is no way around it. This effort is not a one-time affair; an installation tool is not daily used; so sadly for each major release the programmer has to start learning again.

Developers deserve a better tool
Developers are not happy with this situation and are constantly searching for better tools, preferably something that is easy to use and powerful at the same time. Vendors of installation tools try to solve the problem by extending the ’no programming required’ paradigm, adding additional parameters, wizards, templates and expensive training, but this only increases the labyrinth for the programmer. 

The obvious solution is to solve the real problem, to base the installer on a real language, preferably the language a developer daily uses.  A balanced tool based on a powerful parameter system working smoothly together with a general purpose programming language.
LizaJet Installer is that tool.