I used 3 keywords together. free & open source & active. The modules I checked some ago on CodePlex looked what it seems skeleton modules, not finished ones. It's like.. here's what I did.. you go finish it and polish it.  I posted another post about SmartSocial. I have never used it but it looked like it can be extended and moved forward by the developer community. If the original developer stopped working on it and I am getting the impression he did, why doesn't the corp adopt it and include it in the DNN distribution. This will drive more people to use DNN.

As for the perception that software running on Windows can't or shouldn't be free, that needs to go away. In the older days where everything from Microsoft costed money, hosting asp or asp.net sites was expensive, this is not true anymore. Visual Studio Express and SQL Server Express are free so developers can develop and produce quality software with free tools. ASP.NET with SQL Server hosting is very affordable. You can get hostng for less $5/month. CodePlex is a big repository for open soource Windows software. There's no more excuse that there's a barrier for entry to do Windows development.

The only cost is Windows. People buy computers with Windows preinstalled and it's not like they have to factor out its cost. Once they have the computer, they can start developing with free tools.

This is exactly how free open source works... don't expect... do.
Otherwise expect to make a contribution to somebody else's living requirements.

I think there are simply more paid professionals using Windows software than hobbyists and enthusiasts in terms of ratio than say Linux based software. Pro's generally expect to get paid - eventually.

That's because far more organisations use Windows than Linux on their desktop.

Linux may also have a support model that is better understood and accepted within its community.... therefore "free" software is good because (hopefully) people will pay for support contracts. In the Windows world this business model is less understood, hence the need for an upfront fee a lot of the time. ("Free" to a Windows user might imply lack of quality, whilst to a Linux user it may imply that it's better quality).

Linux users are probably more relaxed when paying for support when they need it, rather than paying for a product for an up front fee. Not so Windows users.

I think on the whole it's just a cultural issue within the OS's, and it's mainly an illusion without much basis of reality.
Check out google's business model for instance which seems to invert everything, we will probably get Google's "OS" for free in 2012.

http://www.theregister.co.uk/2009/07/08/google_microsoft_phony_chrome_war/