John Loiacono has been chosen to replace Jonathan Schwartz as head of Sun's software business.
Previously senior vice president of Sun's operating platforms group, Loiacono, 43, will fill the post of executive vice president vacated by Schwartz, who was promoted last week to president and chief operating officer.
Loiacono will lead the division responsible for delivering on Sun's network computing strategy and will have particular responsibility for boosting the growth and acceptance of Java and the Solaris operating system.
The move comes at an important time for Sun. The firm has started to make inroads onto the desktop with its low-cost Java Desktop System and last Friday unveiled a $1.6bn agreement with Microsoft settling technology and antitrust disputes.
Loiacono will have the job of finalising details of Sun's new technology partnership with Microsoft and ensuring that the once bitter enemies make their software products work together.
"We will build on our new collaboration with Microsoft and plan to provide the most Microsoft-interoperable software available, while continuing to focus on delivering end-to-end network solutions - from the data centre and desktop environments to mobile devices and smartcards," said Loiacono in a statement.
As senior vice president of Sun's operating platforms group Loiacono, who has been with the company for 17 years, was responsible for the strategic direction of the Solaris and Linux platforms, as well as the Java Enterprise System.
Before that he held the position of chief marketing officer, where he managed Sun's overall brand, marketing and communications strategy.
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago