One of Milo's friends at the start-up, Skullbocks, used his Powerbook G3 to monitor their web site's performance and to view a video news feed.
It looks like the G3 is running Linux.
Year of feature (shown above)
That is an Old version of KDE, perhaps version 2.0
Looks to be an old version of GNOME actually.
I believe it's KDE. At some point the main character listed running processes, and there were kwm, kpanel, etc.
Here's what I found on the movie's IMDB page:
"When Milo is seen accepting awards, he is accepting them from Scott McNealy of Sun Microsystems and from Miguel de Icaza, creator of GNOME and Vice President of Developer Platform at Novell."