FQA 0 - Introduction to Plan 9
0.1 - What is Plan 9?
Plan 9 is a research operating system from the same group who created UNIX at Bell Labs Computing Sciences Research Center (CSRC). It emerged in the late 1980s, and its early development coincided with continuing development of the later versions of Research UNIX. Plan 9 can be seen as an attempt to push some of the same ideas that informed UNIX even further into the era of networking and graphics. Rob Pike has described Plan 9 as "an argument" for simplicity and clarity, while others have described it as "UNIX, only moreso."
From The Use of Name Spaces in Plan 9:
Plan 9 argues that given a few carefully implemented abstractions it is possible to produce a small operating system that provides support for the largest systems on a variety of architectures and networks.
From the intro(1) man page:
Plan 9 is a distributed computing environment assembled from separate machines acting as terminals, CPU servers, and file servers. A user works at a terminal, running a window system on a raster display. Some windows are connected to CPU servers; the intent is that heavy computing should be done in those windows but it is also possible to compute on the terminal. A separate file server provides file storage for terminals and CPU servers alike.
The two most important ideas in Plan 9 are:
private namespaces (each process constructs a unique view of the hierarchical file system)
file interfaces (familiar from UNIX, but taken to the extreme: all resources in Plan 9 look like file systems)
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