Collaboration is two or more people working together towards a common goal.
The Free and Open Source Software community is an almost text book example of a truly collaborative community. By using organically developed collaborative processes, the Free and Open Source Software community has produced software that has formed the backbone of the internet as we know it, as well as well known projects such as the Firefox Web Browser and the Linux Operating System.
Quality and Support
While I personally use Free and Open Source Software for a variety of reasons, the two reasons I have built my business and offerings on it are:
Support:
Because the source code is freely available it is much easier for my clients to move to another provider if they feel that the services I offer no longer meet their needs. Now this may sound counter intuitive for a business owner to make it easier for his clients to leave, however I cannot in all conscience inflict vendor lockin on my clients when I loathe it so much in my own life.
Quality:
The projects I tap into to provide the services I do are all mature, well developed and well supported.