Sun today said that it has reached a milestone of six million licenses for its Solaris 10 operating system since the software’s release in January 2005. The company claims that this number represents more than the combined shipments of all Red Hat Enterprise Linux, IBM AIX and Hewlett Packard HP-UX releases over the same period.

Sun recently detailed the virtualization features of Solaris 10, which includes logical domains that enable users to run up to 32 Solaris copies within "Solaris containers" on one T1 processor-based system.