The tension has ratcheted up a couple of notches since Microsoft, along with Intel Corp., Digital Equipment Corp. and Compaq Computer Corp. demanded on Sept. 11 that Sun hand over Java to an international standards body.
It hit a flash point earlier today when Sun CEO Scott McNealy tossed a threat Microsoft's way, telling CNBC that Microsoft was close to violating its license agreement for Java, and that Sun might revoke the license.
A Sun spokeswoman confirmed that the threat wasn't an empty one. She said Sun will review how Java is being utilized in Microsoft's Internet Explorer 4.0, scheduled to be released Sept. 30. "We'll know next week if there is a violation," said Lisa Poulson.
She would not speculate on what would happen if Sun judges Microsoft to have breached its Java license agreement.
Microsoft scoffed at the notion. "It's hard to see on what basis he's making that statement. He should really put up or shut up," said Charles Fitzgerald, group program manager at Microsoft in Redmond, Wash. He added that Microsoft plans to continue working with Java, which "has some real value as a programming language."
Is dealing with Sun a hassle?," he continued.
"Absolutely. Do its antics undermine its credibility as a standards keeper? We think so."
At a press conference Monday morning, executives at JavaSoft, the Sun subsidiary in charge of the Java programming, responded in strong terms about Microsoft's desire to keep its "monopoly" and accused Microsoft of grandstanding by sending an open letter asking Sun to respond to the International Standards Organization.
"Hurling insults at Microsoft doesn't exempt Sun from meeting the requirements of the international standards community," said Fitzgerald. "They can rant and rave about Microsoft, but this isn't about Microsoft, it's about whether Sun can respond to the standards body."
Sun planned to post responses Monday to comments it received when the ISO turned down its request to be Java's steward in July.
The central issue involving the two concerns whether Sun can turn Java into an operating system, said Ted Schadler, an analyst at Forrester Research Inc. in Cambridge, Mass.
In the end, Schadler said, "it's a war of words, signifying nothing."
In particular, Schadler thinks Sun will avoid any MacBethian maneuvers by forcing Microsoft to dump Java Virtual Machine from its Internet Explorer browser.
"I'd be shocked if Sun were to say to Microsoft, `you can't run the next-generation Java Virtual Machine,'" Schadler said.