Yes GNU spends a lot of time improving performance. A couple of examples from the most recent release, which you might think were too simple to optimize significantly:<p>The yes command (which is generally useful for generating repetitive text):<p><pre><code>    $ yes-old | pv &gt; &#x2F;dev&#x2F;null ^C
    ... 55.8MiB&#x2F;s ...
    $ yes-new | pv &gt; &#x2F;dev&#x2F;null ^C
    ... 3.44GiB&#x2F;s ...
</code></pre>
Details on that fairly simple change are at <a href="http:&#x2F;&#x2F;git.sv.gnu.org&#x2F;gitweb&#x2F;?p=coreutils.git;a=commitdiff;h=35217221" rel="nofollow">http:&#x2F;&#x2F;git.sv.gnu.org&#x2F;gitweb&#x2F;?p=coreutils.git;a=commitdiff;h...</a><p>Also we more than doubled the speed of wc -l (by avoiding function call overhead):<p><pre><code>    $ yes | pv | wc-old -l ^C
    ... 230MiB&#x2F;s ...
    $ yes | pv | wc-new -l ^C
    ... 558MiB&#x2F;s ...
</code></pre>
Also we now generate an infinite stream of integers more efficiently too:<p><pre><code>    $ seq-old inf | pv &gt; &#x2F;dev&#x2F;null ^C
    ... 13.3MiB&#x2F;s ...
    $ seq-new inf | pv &gt; &#x2F;dev&#x2F;null ^C
    ... 497MiB&#x2F;s ...</code></pre>