http://man.cat-v.org/plan_9/1/emacs
Plan 9 is more Unix than Unix. First, Acme is no longer written in Alef, but in C (on Plan 9) or Limbo (for Inferno). Second, I don't think you understand how Acme works; try reading the Acme paper or watching Russ Cox's introductory screencast.
What about Acme's architecture?
> Acme is about 8,000 lines of code in Alef, a concurrent object-oriented language syntactically similar to C [Alef]. Acme’s structure is a set of communicating processes in a single address space. One subset of the processes drives the display and user interface, maintaining the windows; other processes forward mouse and keyboard activity and implement the file server interface for external programs. The language and design worked out well; as explained elsewhere [Pike89, Gans93, Reppy93], user interfaces built with concurrent systems can avoid the clumsy top-level event loop typical of traditional interactive systems.
That does not sound like Unix philosophy. Communicating processes in a single address space application. On Plan 9. Written by Rob Pike at Bell Labs.
We've seen companies like SUN, IBM, HP, DEC/Compaq/whatever they are called now/..., etc. earning zillions on big fat applications. Big fat GUI applications and big fat server applications.
From any Oracle DB, to any Java application, to basically every desktop application - none follows the so-called 'UNIX philosophy'. Thus tools like GNU Emacs have zillions of similar applications under UNIX and GNU Emacs is nothing special at all.