Mihai Parparita is asking on Mastodon:

What are good examples of early Mac OS X software (10.0-10.4 era, pre-Intel switch)?

Then providing the initial list.

• OmniWeb, OmniGraffle, OmniOutliner and other Omni Group software
• Transmit 2, Unison, Candy Bar, Pixadex, and other Panic software
• Audio Hijack and other Rogue Amoeba software
• NetNewsWire and MarsEdit
• Watson
• Acorn
• TextMate
• Quicksilver
• VoodooPad
• BBEdit
• SubEthaEdit
• GraphicConverter
• iCab
• Camino
• Fetch
• Default Folder X
• MenuMeters
• DEVONthink
• CodeWarrior
• Resorcerer
• FruitMenu, WindowShadeX and other Unsanity haxies
• LiteSwitch X
• DragThing and PCalc
• TinkerTool
• LaunchBar
• Path Finder
• Konfabulator

Good memories, although most if these are still alive and well.