What’s the difference between a paid contributor to a FOSS project and a volunteer contributor?

FOSSBazaar recently highlighted Evangelia Berdou's doctoral thesis on the differences between the contributions of paid open source developers and volunteer contributors.

Software Freedom Day (SFD) is a worldwide celebration of Free and Open Source Software (FOSS). Our goal in this celebration is to educate the worldwide public about of the benefits of using high quality FOSS in education, in government, at home, and in business -- in short, everywhere!

Many of these problems are with volunteer software in general, not Free Software in particular. Hobbyist proprietary programs are often hard to use for many of the same reasons. But the easiest way of getting volunteers to contribute to a program is to make it open source. And while thousands of people are now employed in developing Free Software, most of its developers are volunteers.

The headline says "Why Code For Free", but it's really more complicated than that because there are many FOSS developers who are paid to work on FOSS projects. In this final part of our series, more developers speak on the rewards of being part of the FOSS community.

The Linux Foundation has found that the number of developers putting work into the Linux kernel is growing fast, tripling over the past three years. Over that period, the number of individual contributors has doubled. Linux is being used more often as the firmware found in consumer electronics, and now more than 70 percent of all kernel development is done by paid professionals.

Andy Updegrove writes an article providing an overview of the history of FOSS and its champions, the major philosophical differences that divide FOSS from OSS developers, the multiple licenses under which FOSS is made available, and the principle non-profit institutions that support and promote FOSS.

I am looking at a claim thats usually made against many outspoken people in the FOSS, but often you see it when there is no counter in an debate/argument. When I first started writing this article little did I know I would get my own example of “killing the FOSS” directed at me.

This document presents information about patents and patent liability useful for developers working on community distributions of Free and Open Source Software (FOSS).