A great place to learn more about Open-Source and the free software movement is RedHat's OpenSource.com. This site provides excellent resources to learn about free or open software. It also provides an excellent community to get connected with Open-Source developers and learn about their projects and experience.
If you are interested in moving to an open model, the Open-Source Initiative provides some greate starting points and guides tailored for everyone from the developer to the businessman, to the average user.
Explore Open-Source Projects
There are a number of Open-Source companies, though you may not have heard of them, that have developed some of the biggest infrastructures and have become some of the most successful background tech companies of all time. These include operating system companies like Canonical, the company behind the operating system Ubuntu that drives many businesses and computers including retail giant Walmart. RedHat is the the leader in Open-Source for businesses, and maker of RedHat Enterprise Linux for Corporations, an operating system that rivals that of Microsoft's Windows OS.
Even more obscure companies like the Document Foundation, makers of LibreOffice, the Open-Source alternative to Microsoft Office, help to power the internet. Equally important is the Apache Foundation, makers of the Apache Web Server that serves more than half the internet.
The point we are trying to make is that Open-Source companies are everywhere, you just have to look.