I didn't find this posted previously so I thought some people would be interested in these. They basically talk about prey in 1998 and show you the tech demos for it. In one part of the second video they show in their demo how you can create your own portals whereever you want, which is just like what valve is doing in "portal", I wonder why they didn't implement that feature in prey when they had the capability even back then. Ahh well, cool to see how things were back 8 years ago anyway..
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Video 2
Video 1
Video 2