Sun Microsystems Inc. officials on Tuesday offered new details on its open-source strategy. The company said publicly what most industry players understood for a long time: Sun"s top priority is supporting its Solaris operating system rather than Linux. At a briefing in San Francisco ahead of this month"s launch of Solaris 10, John Fanelli, the senior director of marketing for Sun"s network systems group, told reporters that Sun"s upcoming Solaris 10 would be cheaper than, say, a Red Hat Inc. Linux solution.