At least, that's what Staley Cates, president of Southeastern Asset Management, told investors last June, after his company acquired 10 percent of Sun's stock.

"Sun Microsystems is kind of interesting because it's progressively less of a server company and more of a software company; it's more about Solaris and Java," Cates said at a for the Longleaf Partner Funds that his company manages. "And that's kind of a change that we don’t think the market's on to at all."

Although Sun still generates the vast majority of its revenue from server and workstation sales, CEO Jonathan Schwartz may now be paying special attention to Cates' message.

Southeastern has been increasing its stake in Sun this year, and on Wednesday it said it had changed its ownership status in the company in a way that allows it to take a more active hand in its management, according to a filing with the U.S. Securities and Exchange Commission. It also said it has been meeting with Sun's management to talk about ways to "maximize the value of the company."

"We welcome feedback from our shareholders and welcome their insight," a Sun spokeswoman said Wednesday. Neither Sun nor Southeastern Asset Management would elaborate on what was discussed at the meetings. Southeastern Asset Management, based in Memphis, Tennessee, does not focus exclusively on technology stocks, but it has also invested in Dell, Symantec and Level 3 Communications.