This is the Apple Developer CD Series as of October 2001, including
Mac OS 9.2.1 and Mac OS X 10.1 for PowerPC with inherent Developer
Tools CD-ROM.

A note about the downloads available from above:

 1. file is the Mac OS X 10.1 Installation CD-ROM ("DevOct2001CD1.toast.zip")
 2. file is the Mac OS 9.2.1 Installation CD-ROM ("DevOct2001CD2.toast.zip")
 3. file is the Developer Tools CD-ROM ("DevOct2001CD3.toast.zip")

A note about the manual download available from above:
The manual download above contains a complete scan of the folded paper
sleeve (7.9 MB).

Compatibility
Architecture: PPC PPC (Carbonized)

Excerpt from the Mac OS 9.2.1 Readme:

> You can install this version of Mac OS 9.2 on any of the following
> computers: Power Mac G4, Power Macintosh G3, PowerBook G4, PowerBook
> G3 (except the original PowerBook G3), iMac, and iBook.

Mac OS X 10.1 adds the following requirements:
128 MB of RAM, 1.5 GB har disk drive space available.

Mac OS X 10.1 Installation hint:
The Mac OS X 10.1 CD-ROMs has been charged for shipping costs only.
This was a cost-free update to Mac OS X 10.0, and even this Developer
Series CD-ROM requires Mac OS X 10.0 already installed.