The Microsoft remedy hearing continues with witnesses from major high-tech companies claiming Microsoft's monopolistic practices harmed their business.

RealNetworks executive Dave Richards alleged his company had been harmed. Microsoft's software-licensing terms are “severe and onerous”, he said. He claimed RealNetwork's business had been affected by Microsoft's Windows licensing contracts with PC makers.

Since the summer of 2000 the company has been unable to convince manufacturers to pre-install Real's software on their machines – this is directly attributable to Microsoft's licensing contract for Windows, he claimed. Microsoft has been trying to convince manufacturers to favour its own Windows Media Player above competitive multimedia solutions, he alleged.

Peter Ashkin, of AOL brand products at AOL Time Warner, testified as a former executive of PC manufacturer Gateway. He said Microsoft had removed that company from its list of approved vendors, as Gateway had chosen to install Linux on its Connected Touchpad Internet appliance.

He said: “I was told we were a bad partner – we used Linux on products.” He also testified that Gateway believed it was not getting as good a deal on its Windows licence as other PC makers.

Michael Tiemann, chief technology officer of Linux supplier Red Hat, discussed meetings he had with Dell, Compaq, HP and IBM to encourage manufacturers to install Linux on their products.

Whenever he mentioned GNOME – Linux's UI for desktop PCs – during these meetings, he noticed a change, he said: “I observed the tone of the discussions changed,” Tiemann said, adding that it was like “a skunk had walked into the room”.

“Based on my experience (I concluded that) the topic of Red Hat as a desktop operating system is essentially a taboo topic among OEMs (original equipment manufacturer)” he observed.

He believes PC manufacturers were afraid to offer non-Windows systems on their desktop computers.

The hearing continues next week.