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A quick trip to the year 2002: BeOS 5
(raduzaharia.medium.com)
I remember running BeOS and thinking it was much better at the time then the popular Linux flavors but it just didn't have much more going for it once you had it installed. The GUI was much better and it was stable. Sad that it didn't make a bigger mark and have a lasting presence.
Discussions on vintage and retrocomputing