Everybody has listened about WordPress and their evolution as Open Source example of their success in the market. For the consumer to consumer market WordPress is the leader in some of the main areas, no doubts.
I would like to write about a different way to use the open source in the market: Drupal & Acquia. Read the evolution of Acquia, they are using Drupal to compete with the corporate WCM solutions and multi-channel e-commerce in the medium/big companies.
Drupal is not trying to compete against WordPress. The mistake I have seen reading articles and talking with people is that they misunderstood the use and capabilities where Drupal can really compete.
Acquia understood it, and they has been able to penetrate in a market composed by standalone solutions with high total cost of ownership (TCO): Adobe, EMC, SharePoint…
They have been evolving through last are shown as leaders in the Gartner Magic quadrant.