Is Rob Glaser Microsoft's worst nightmare?

Was he settling old scores or was he simply a reluctant witness who wanted nothing more than to be back home working on new code?

Either way, he came to town packing a bombshell.

"I have no axe to grind," said Rob Glaser, the soft-spoken chief executive of Real Networks, who said he still has a lot of friends working at Microsoft Corp.

It's likely he has a few less friends at his old company than he started with. That's because Glaser's testimony before the Senate Judiciary Committee Thursday morning is likely to cause Microsoft a gigabyte's worth of grief over the coming weeks and months.

'I have no axe to grind.' -- Real Networks CEO Rob Glaser

Senator Orrin Hatch, the Judiciary Committee chairman, has been searching for a smoking gun -- something that he could point to as proof positive of Microsoft's illegal business practices. During a similar hearing last March, the committee was treated to pyrotechnics, including a riveting exchange between Hatch and Microsoft CEO Bill Gates.

But Hatch failed to find the evidence he sought. He alluded to that at one point during Thursday's hearing, noting that computer companies are hardly breaking down the door to his office to testify.

That's why Glaser's testimony -- alleging Microsoft is deliberately trying to break Real Networks multimedia software product -- is all the more important to the committee. He's the first witness to come before the committee armed with more than generalizations about Microsoft's business practices.

"Believe me, testifying in this matter publicly is not something we wanted to do. It's not our modus operandi," he said. But Glaser said Microsoft had forced his hand by not responding to his complaint in a meaningful way.

And now, he added, Microsoft's actions will slow down innovation on the Net -- unless somebody stops them.

Settling old scores?
Microsoft said the charges are untrue and accused Glaser of "creating controversy where none exists." Microsoft said its product, Windows Media Player, does not disable the Real Networks Real Player and "does not in any way stop any existing player on the user's machine from working."

Could Glaser be settling old scores by blowing up a minor dispute? One Microsoft source who knows Glaser thinks so. He describes Glaser as fiercely bright -- always thinking, always smart, always trying to be a few moves ahead -- but said he is also driven by a desire to take a measure of revenge on his ex-colleagues.

"Rob was very upset when he left Microsoft and is driven by a desire to show up Bill Gates and gain Bill's respect. He'd stop at nothing to achieve it. I like the guy -- he's endearing in his aggressive way. He can be extremely charming or extremely combative."

Microsoft has compounded its problem by its own indecision. The company has tried to work with RealNetworks as a partner, even going so far as to take an equity stake. But sources say senior management is confused about how best to handle Glaser: whether to view him as a partner or as a competitor.

Blood trail
Real Networks was never confused about the lay of the land. Glaser has always treated Microsoft as a competitor and has played it off against Netscape Communications Corp. when it could.

Yet all that business intrigue may be beside the point. Hatch, who plans further hearings, has picked up the blood trail and intends to keep up the pursuit. And that promises more trouble for Microsoft.