Linux vendor Red Hat is out this week with the second major milestone for the next generation of its enterprise Linux release, Red Hat Enterprise Linux 6 (RHEL), as the Linux player ramps up development for its flagship operating system. The development of RHEL 6 has been closely watched as Red Hat (NYSE: RHT) seeks to grow its already sizable share of the enterprise Linux market, though the company remains cagey over an exact release date. When it ships, RHEL 6 will provide new performance, virtualization and hardware enablement for Red Hat's enterprise users.