The ticker symbol allows investors quickly to locate a company on the exchange. The previous acronym stood for Stanford University Network Workstation, from Sun's roots in building workstations.
The change is merely symbolic and does not affect Sun's day-to-day business. But Sun chief executive Jonathan Schwartz said in a blog posting that the move represents the growing importance of Java.
"Java touches nearly everyone who touches the internet. Hundreds of millions of users see Java, and its ubiquitous logo, every day," he wrote.
"On PCs, mobile phones, game consoles - you name it. Wherever the network travels, the odds are good that Java is powering a portion of the experience."
Java is on of the most prevalent technologies around today, spanning mobile phones, enterprise servers and client computers.
"The number of people who know Java swamps the number of people who know Sun. Or SUNW," said Schwartz.
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