While the popular macOS sees updates nearly annually now, there was a time where Apple struggled for years to get a major update out.

Clips in order of appearance:
Apple 1984 Ad Commercial (5:29) -    • Apple 1984 Ad Commercial - Original R...  
Mac OS 8 Demos (6:43) -    • Mac OS 8 (code name Copland) Demos  
Macworld San Francisco 2000 (11:09) -    • Macworld San Francisco 2000-The Mac O...  
WWDC 2002 Death Of Mac OS 9 (11:43) -    • 2002 05 06 WWDC 2002 Death Of Mac OS 9  

Music Used:
You're not that Funky - Otis McDonald (0:00)
Tiptoe Out the Back - Dan Lebowitz (0:38)
Rank and File - Silent Partner (3:26)
Handprints - John Deley and the 41 Players(5:42)
Fuzzy Feeling - Everet Almond (7:17)
You Had To Be - E's Jammy Jams (9:03)
Cologne 1983 - Josh Kirsch (10:47)
Feel The Funk - Jimmy Fontanez (12:14)