<p><pre><code>  &gt; Some Plan 9 ideas have been absorbed into modern Unixes, particularly the more
  &gt; innovative open-source versions. FreeBSD has a &#x2F;proc file system modeled
  &gt; exactly on that of Plan 9 that can be used to query or control running
  &gt; processes. FreeBSD&#x27;s rfork(2) and Linux&#x27;s clone(2) system calls are modeled on
  &gt; Plan 9&#x27;s rfork(2). Linux&#x27;s &#x2F;proc file system, in addition to presenting process
  &gt; information, holds a variety of synthesized Plan 9-like device files used to
  &gt; query and control kernel internals using predominantly textual interfaces.
  &gt; Experimental 2003 versions of Linux are implementing per-process mount points,
  &gt; a long step toward Plan 9&#x27;s private namespaces. The various open-source Unixes
  &gt; are all moving toward systemwide support for UTF-8, an encoding actually
  &gt; invented for Plan 9.

</code></pre>
This is interesting. Anyone know of other ways Plan9 has influenced Linux etc. since 2003?