Yes, in a way open source acts as a vibrant market of competitors forcing proprietary products to innovate where they may have been willing to stagnate, and in a way immune to some of the more anti-capitalistic ways of preventing innovation (e.g. buying out the main competitors). As unions worked to combat some of the major criticisms of capitalism by Marx (as I understand it), open source works to combat some of the major criticisms of companies in the software market (patents are put in an interesting light in this theory).