The problem (IMNSHO) with Vlassis Rizopoulos' work is that he chose to create his installer using a proprietary product, namely InstallAnywhere's ZeroG.
That means that only people with a license to ZeroG will be able to work on that installer and make future improvements to it.
There are several open source installer builders out there. I haven't worked with any of them, so I can't say how good X or Y are, but relying on a proprietary product doesn't sound like a good path.
-Roberto
