The original paper on acme is here: http://doc.cat-v.org/plan_9/4th_edition/papers/acme/

Acme was different to the 'sam' editor and most other Plan 9 programs up to that point (aside from its predecessor, "help", a similar system that was replaced by acme).

Look up a YouTube of somebody using it and discussing its features. Basically you could mount computational resources like cpus/ram/network/etc from an external resource server. It also had a graphical equivalent to the Unix pipe between applications.