When comparing NetBSD vs Plan 9, the Slant community recommends NetBSD for most people. In the question“What is the best operating system for a developer?” NetBSD is ranked 7th while Plan 9 is ranked 11th. The most important reason people chose NetBSD is:
It adheres to traditional Unix and new defined standards.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Adhere to the standard
It adheres to traditional Unix and new defined standards.
Pro It's Open Source
It's open source with a BSD License, which is much more business friendly than GPL. It's the real ancestor of Mac, that is being used nowadays.
Pro It's real
Under NetBSD csh is csh not tcsh; also vi is real vi not elvis, nvi or vim. It's ideal for purists.
Pro Architecture portability
It's the most portable OS in the world when considering what architectures it can run on. It runs on very wide range of hardware, from toaster to satellites. This of course does not mean it supports drivers for many consumer facing products making it a difficult solution to just boot up and use when compared to other OSs.
Pro Clean source code
It prioritizes source code cleanliness over anything.
Pro Well designed
Plan 9's design is very orthogonal and well done.
Pro Designed to allow for multiple computers to work as if they were one
With Plan 9, computers are turned into terminals where you can access files and processing units which can be located elsewhere. Data storage is handled by another external server. This means that instead of each person having their own individual computer with all the required parts, all of the computing and storage is done in a central area and everything is networked in together.
Cons
Con Lack of drivers
It lacks drivers for some new devices.
Con Difficult to use software made for other systems
Plan 9 is very different from most other operating systems, and as such it's extremely difficult to bring in software designed for other operating systems ('porting').
Con No fully featured web browser
As indicated on the official Bell Labs webpage, there is no full featured web browser currently working on Plan 9, except abaco.
Con Not supported by most tools
Not supported by most dev tools beyond text editors.