I am attracted in what the benefits of open software model are to original software writers (not users). I more or less know the concept from users standpoint (they can modify it, just like Linux, etc.) What I want to know is what would a developer gain by releasing his software into community. He cannot charge for it anymore, even if he still holds IP rights like patents. Charging for support, not licenses? Quick market penetration? What else? Thanks.
Best answer:
Answer by Abhi
You can give your software for free to individuals, but can charge money to professional users. Many open source software writer writes programs for fun, as they are already working in some IT company. So they are not attracted in money. Like google you can get traffic, by availing the free software from your website. More traffic means more advertising. I stole this thought from google. Or else you can publish trial version for free, but can charge money for pro version.
In the end I also don’t know what are the right benefits, so plz question others and thnx for 2 points. 
Know better? Leave your own answer in the comments!
Customers. He charges for maintenance, usually. Also Open Source programs are often tickets to huge money jobs at companies like Google or, in the case of the Mach kernel writer (Mach kernel being the one that runs Mac OS X GNU Hurd and GNU Darwin) a job at Microsoft. Miguel de Icaza was really hired by Microsoft, but US Immigration said “You can’t have him because he never went to institution” so he co-wrote the GNOME desktop and now he works for Novell.
Open Source Software is a calling card. Red Hat is doing very well as an Open Source company so don’t knock it.