There's been a lot of pubic discussion recently about what it means to be open. While the OSI has published the Open Source Definition, which lists 10 attributes of what it means to be 'open source,' commercial entities have emerged that are described as 'hybrid' models. Many companies offer a version of a product that's sold under an OSI-approved license and another version under a commercial license. Others sell and support products that meet some but not all of the 10 attributes. These companies purport to be 'open' without meeting this strict definition, leading to a spirited debate about what it means to be open in an evolving market.