Apple Operation System Codenames

System 6
System 6.0.4: Antares
System 6.0.5: Big Deal
System 6.0.6: SixPack
System 6.0.8: Terminator

System 7
System 7: Blue, Big Bang, M80, Pleiades
System 7 Finder: Furnishings 2000
System 7 Tune-Up: 7-Up
System 7.0.1: Road Warrior (in reference to PowerBooks), Beta Cheese
System 7.1: Cube-E, I Tripoli
System 7.1 Pro: Jirocho
System 7.1.2: Rock & Roll
System 7.5: Mozart, Capone
System 7.5 Update 2.0: Thag, Thor
System 7.5.1: Danook
System 7.5.2: Marconi
System 7.5.3 for PPC and PowerBooks: Juno
System 7.5.3 Revision 2 Update: Buster
System 7.5.3 Revision 2.2 Reference Release: Unity
System 7.5.3 unreleased: Bloom County
System 7.5.3 CPU Update: Thag, Zeus
System 7.5.4: Son of Buster (original Son of Buster, but never released due to a bug)
System 7.5.5: Son of Buster
Mac OS 7.6: Harmony
Mac OS 7.6.1: Ides of Buster

MacOS 8
MacOS 8.0: Tempo, Maxwell
MacOS 8.1: Bride of Buster, Scimitar
MacOS 8.1 for iMac: Men in Black
MacOS 8.5: Allegro
MacOS 8.5.1: The Ric Ford Release
MacOS 8.6: Veronica
MacOS 8.6 alpha: Hammerfest, Horatio

MacOS 9
MacOS 9 Beta 3: Signed
MacOS 9 Beta 4: Sealed
MacOS 9.0: Sonata
MacOS 9.0.1: Duet (unreleased)
MacOS 9.0.4: Minuet
MacOS 9.1: Fortissimo
MacOS 9.2 alpha: Slurm!
MacOS 9.2: Moonlight
MacOS 9.2 special CPU support version for PowerMac G4 QuickSilver: Starlight
MacOS 9.2.1: Limelight
MacOS 9.2.2: LU1

MacOS X
MacOS X: Cyan, Siam
MacOS X Public Beta: Kodiak
MacOS X 10.0: Cheetah
MacOS X 10.1: Puma
MacOS X 10.2: Jaguar
MacOS X 10.2.1: Jaguar Red
MacOS X 10.2.2: Jaguar Blue
MacOS X 10.2.3: Jaguar Green
MacOS X 10.2.4: Jaguar Pink
MacOS X 10.2.5: Jaguar Plaid
MacOS X 10.2.6: Jaguar Black
MacOS X 10.2.7 for Power Macintosh G5: Smeagol
MacOS X 10.2.7 for PowerBook G4: Blackrider
MacOS X 10.2 for x86 computers: Marklar
MacOS X 10.3 core: Pinot
MacOS X 10.3: Panther
MacOS X 10.4 core: Merlot
MacOS X 10.4: Tiger
MacOS X 10.4.1: Atlanta
MacOS X 10.5 core: Chablis
MacOS X 10.5: Leopard

MacOS X Server
MacOS X Server: Rhapsody
Rhapsody 5.0: Grail1Z4
Rhapsody 5.1: Titan1U
Rhapsody 5.3: Hera109
MacOS X Server CR1: Enterprise
MacOS X Server early developer release: Atlas
MacOS X Server early developer release: Hera
MacOS X Server DR2: Titan
MacOS X Server 1.0: Mac OS Enterprise
MacOS X Server 1.2: Pele1Q10
MacOS X Server 1.2 v3: Medusa1E3
MacOS X Server v10.2: Tigger
MacOS X Server 10.3: Panther
MacOS X Server 10.4: Tiger