A two-year old internal memo from HP warned of an anticipated legal assault by Microsoft against open-source, it emerged on Monday.

The June 2002 memo was sent shortly after HP struck a patent cross-licensing deal with Microsoft. It urges top HP executives to work together on a strategy to protect HP from the fallout of lawsuits stemming from its use of open-source technologies that might infringe on Microsoft patents.

"Basically Microsoft is going to use the legal system to shut down open-source software," memo author Gary Campbell wrote. "We don't have to exit selling to the open-source market, but we need to plan smartly where to reduce our exposure."

Campbell was at the time HP's vice president of strategic architecture. He is now its vice president of enterprise servers and storage. His memo was printed on NewsForge.

HP confirmed the note's authenticity but downplayed its importance. Microsoft did not immediately return calls seeking comment.

"As this memo was created over two years ago, we believe it is not relevant today," spokeswoman Elizabeth Phillips wrote.

She highlighted HP's ongoing commitment to Linux and other open-source technologies - it was one of the first companies to indemnify its customers against The SCO Group's lawsuits - as well as its strong partnership with Microsoft.

Despite that longstanding alliance, Campbell worried that HP would be on Microsoft's hit list. His memo speculated that Microsoft would launch its legal fusillade within the next few months, after it resolved its lingering antitrust issues.

"They are specifically upset about Samba, Apache and Sendmail. We believe Samba is first," he wrote. Campbell also forecast that Microsoft rivals building around open-source technology, including Intel, Red Hat, Oracle and SuSE (since acquired by Novell), would be targets.

Linux suit

Campbell's memo was sent nine months before SCO launched a lawsuit against IBM over Linux technology SCO claims infringes on its Unix ownership. That case, which is not scheduled for trial until late 2005, is viewed by the industry as a bellwether for infringement claims over open-source technologies.

Microsoft, meanwhile, has spent the past year stomping out legal fires rather than lighting new ones. A court decision last month ended one of the few remaining cases against Microsoft for antitrust violations, and in April Microsoft agreed to spend nearly $2 billion on a settlement resolving all outstanding litigation with longtime foe Sun. It followed that with a $440 million payment to end another case with InterTrust Technologies.

"The company's legal strategy right now is one of settlement," said Jupiter Research analyst Joe Wilcox. "From a public relations standpoint, I wouldn't consider suing the open-source folks to be the best tactic for Microsoft to take."

Thanks to SCO, Microsoft can benefit from uncertainty about Linux's legality without risking its own legal offensive, Wilcox noted.

"From a technology perspective, Microsoft is doing its just-the-facts campaign, trying to show the benefits of Windows versus open-source. One of the benefits Microsoft touts is the clarity of the licensing - there is a point of accountability," he said.

"Regardless of its legitimacy, the SCO lawsuit has raised questions about the open source IP (intellectual property) licensing model, and that's something Microsoft has been quick to take advantage of in its marketing."