The 4.x series was the one where the ideas still making Plasma so powerful were seeded. While I loved KDE 3 the design for 4 seemed revolutionary. Too bad it was alpha/beta quality up until the 4.6 release years later. I fared through all the bugs, crashes and performance issues with a young student's determination (while running Fluxbox on the side) but I can very well understand people doing serious work had limited patience for the issues.
Anyhow, happy anniversary from a long-time KDE user!
Anyhow, happy anniversary from a long-time KDE user!