As Sun Microsystems' JavaOne conference kicks off this week, along with its CommunityOne open source conference, Sun and the OpenSolaris community have jointly announced the availability of the OpenSolaris operating system. It's a fully open source open, community-driven operating system, based on Sun's Solaris kernel. You can download it free now. There is more news out of Sun today, too, including a hookup between Amazon and the OpenSolaris community, focused on cloud computing applications. Can this OS compete with Linux rivals?