Massive amounts of effort were poured into these historical operating systems and now they are obsolete. But obsolescence does not diminish the craftsmanship, skill, and ingenuity that went into their development. By admiring what the developers accomplished, you are allowing the legacy to live on.

I admit I have a soft spot for software that didn't stand the test of time. I was once on a team that developed a product that was killed in favor of another product. Reading the history of Windows Longhorn (and how much effort was thrown away), I felt a connection with these developers who no doubt felt similar disappointment.