They declared war on Microsoft's operating system with their browser in the mid-90's. They thought they would relegate the operating system to some sort of generic background functionality as the browser took over the desktop. Rather than roll over, Microsoft responded by absorbing the browser into their operating system. To be sure, they responded agressively to the challenge. Netscape cried foul and ran to the Feds for help. Does that make them Liberal? I'd say in a way.
Who is "they"? Netscape never said or did any of these things: it was a bunch of media pundits and nitwits who didn't know squat about computers who speculated about browsers taking over the operating system. But that's bullocks, as there was never any way Netscape could have installed its browser in a way detrimental to Microsoft, and Netscape was only in the browser and web server business; it never claimed to be in the OS business (and it never was, not even as a fantasy).
And I'd not get too worked up about Netscape's "liberalism" since Bill Gates' money has all been going to liberal causes, too - including gun control, if I recall correctly.