I think that's the same implementation, just a port. We had SGI machines running Plan 9, and adjacent SGI machines running IRIX.

-rob

On Sat, Jul 12, 2025 at 9:17 AM Dan Cross <crossd@gmail.com> wrote:

On Wed, Jul 9, 2025, 8:42 PM Skip Tavakkolian <fariborz.t@gmail.com> wrote:
In the 2nd Edition Plan 9, in the Alef Language Reference Manual by
Phil Winterbottom, the title of section 7 is "The Plan 9
Implementation". Were there other implementations?

According to the Alef User's Guide, there was (at least) an implementation for Irix. https://doc.cat-v.org/plan_9/2nd_edition/papers/alef/ug