I forgot who sent the tweet on Twitter but I was pointed to some very interesting research (2005) posted at the Harvard Business School's Working Knowledge site.
Using formal economic modelling, professors Pankaj Ghemawat and Ramon Casadesus-Masanell consider the competitive dynamics of the software wars between Microsoft and open source.
Bryan Ruby is the owner and editor for CMS Report. He founded CMSReport.com in 2006 on the belief that information technologists, website owners, and web developers desired visiting sites where they could learn about content management systems without the sales pitch. Besides this site, you can follow Bryan at Google+ and Twitter.