Apple's official AltiVec emulator for G3 and "G2" (603, 604 and 604e)
PowerPC processors, originally meant for developers to test their
AltiVec-enabled apps until G4 Macs shipped and became commonplace. It
comes in the form of a system extension.

Download #1 is version 1.0a1 (September 1998);
Download #2 is versions 1.0a3 (February 1999) and 1.0a4 (June 1999);

The version number of the extension can be checked with the "Get Info"
command.

If anyone finds more versions (such as the older 1.0d4), please kindly
add them to this page. Thank you.

Compatibility
Architecture: PPC

PPC "G2" or G3 processor(s).

These are the latest known versions for each Mac OS release, at least
officially:
\- Mac OS 8.1 -> 1.0a1
\- Mac OS 8.5 -> 1.0a3
\- Mac OS 8.6 -> 1.0a4