How many of you are using an internally developed installer for your company?

Awhile ago there was a debate whether we should use a third party installer or write our own. We've had 2 generations of internally developed installers that just do services, msmq, com+, gac and sql script by shelling out to exe's.

So I was wondering who out there is using a custom written installer for your companies specific needs? If you have any comments on our approach then let me know.

We have our own installer package and doing it that way is not part of my list of "What not to do..."

While I do agree that many installers have very restricted feature sets and somewhat (cripling) capabilities others offer more flexibility. This being said I have not yet begun to search for alternatives but it will be something I will do in the comming year. I need something in which I can :

1. Create my own modules, plugins or whatever the supported extention model, in a real programming language (java, .NET... whatever, if the supported language of the installer tool starts with the name of the company of the name of the tool this is a MAJOR turnoff)
2. Supports all major versions of Windows.
3. Supports Linux
4. Supports silent installs

I do not think it is too much to ask and I am certain someone did something that will allow me to build on. Also quite certain that there is an open source packaging system that will do just that.

I much prefer maintaining a few specialized tools and plugins than a complete system for multi-platform deployement.

IMHO creating your own of anything should be a last resort option.