What, you want to write a custom action in C#?

It took 2 developers and months of full-time development to create a set of installers with what should have been relatively simple UI and logic customizations. Nobody was happy with the outcome. The WIX builds simply had too many moving parts, causing frequent breakage, and bringing new team members up to speed on the complex build process was a hassle. After about a year of using the old installers, the pain got to be too much and we decided to look for a new solution. Another developer implemented the same custom logic and UIs as in the old installers (plus some additional stuff) by himself in 2-3 weeks using NSIS. And the resulting installer scripts were much simpler.

So what does NSIS have going for it, over WIX, in my opinion?

• Well, to start with, it doesn’t use XML for its syntax. On the surface, NSIS might appear to have a steeper learning curve because it uses its own scripting language. But it really isn’t very complicated(*), and you can get a basic installer working in minutes.
• It’s a very mature installer platform that has been around for years.
• NSIS is used by countless projects, including some very big names, and has a massive community built around it.
• The installer UI is very easy to customize (much more so than WIX, and without the weird compiler errors if a UI element is one pixel off), and there is even a UI designer plugin for Eclipse. 

So if you’re looking for a robust installer framework for your project that won’t break the bank, check out NSIS.

 (*) This isn’t to say NSIS syntax isn’t without its quirks. The lack of variable scoping and the need to push and pop function parameters using the stack, for example, might scare some people away. However both issues are fairly simple to deal with using macros and a little creative naming.