Glyn Moody writes: People have been making money from free software ever since Richard Stallman started selling GNU Emacs on tapes for $150 a time. That's been good for hackers, who have often managed to make a living from their coding by working for one of the startups based around free software. And as companies like Red Hat and Google have grown in size and profitability, so have the credibility and clout of free software. But there is another reason why the success of these new kinds of businesses is so crucial: in many respects they offer a glimpse of coming shifts in other industries that need to grapple with the conundrum of how to make money from goods that are freely available. In particular, they offer the music and film industries an example of an alternative to fighting people's natural instinct to share digital abundance, by making money from new scarcities.