Last year, Microsoft paid $7.5 billion to buy GitHub, the online home of thousands of open source software projects that power apps and sites ranging from Facebook to Walmart.com. The acquisition, along with IBM's $34 billion purchase of open source company Red Hat, proved that open source software can be big business. That's a little surprising since, by definition, open source code can be freely shared by anyone.

Learn about your ad choices: dovetail.prx.org/ad-choices