Is this definitely true? I seem to remember Apple making a big deal about Tiger for Intel being a new OS.
Yes and no.
No commercial versions of Mac OS X prior to Mac OS X 10.4.x for Intel were available for Intel based CPU's.
However, the foundation of Mac OS X (NeXTSTEP, Rhapsody) all had x86 (Intel) releases. Even a Developer release of Rhapsody (which commercially became known Mac OS X Server 1.x) had a full Intel-verison working.
So, the development of Mac OS X (NeXTSTEP, through Rhapsody, to Mac OS X 10.0.x till 10.4.x) has always been developed for x86 "just in case". The first "public developer" release of this Intel-based Mac OS X was Mac OS X 10.4.1 which ran on the Developer Intel "Power Mac": a Pentium IV.
I bet if anyone can get hold of the über-secret Apple-internal Mac OS X 10.0, 10.1, 10.2, or 10.3...
