This is a re-release of the 2nd Edition of Plan 9 from Bell Labs.

2nd Edition was originally released by AT&T in 1995. It was made
available to several universities and was available for purchase for
non-commercial use; it was never released as Open Source. The 2nd
Edition represents a continuous improvement from the first and while
it looks mostly the same in terms of interface, the implementation is
generally much more solid. The original release notes for this edition
can be found at /sys/doc/release2.ms.

Given its age, this release is mostly for educational and research
purposes, although given the inclination and appropriate hardware we
believe you should be able to run it. Note, however, that the 9p
protocol and authentication mechanism have changed between this
release and modern Plan 9, so interoperability might be tricky.

The only changes between this release and the original 2nd Edition
release are the notice, license, and readme files and moving the
original notice file. In particular, any copyright notices attributing
things to AT&T or Bell Labs, or notices on restrictions of their use,
should be read as historical; all such rights have been transferred to
the Plan 9 Foundation and released as open source. Parts (notably, the
fonts) maintain trademark and copyright to their respective parties
(such as Bigelow & Holmes Inc.) and were included in Plan 9 by
permission; those copyrights are unaffected by the transfer to Plan 9
Foundation and remain in effect per the terms found in this
distribution.